Earth system multi-body restriction dynamics model research
Institute of Scientific and Technical Information of China (English)
ZHANG; Qingxian; BI; Siwen; GONG; Huili
2006-01-01
Research provides a theoretical basis for an Earth system multi-body mechanics model and its dynamics, including the Earth system multi-body restriction function and its power, Earth system multi-body restriction under decreasing generalized velocity and decreasing partial palstance, the Earth system multi-body decreasing generalized force, a moving mechanics function, and the Earth system multi-body restriction's wattful and wattless forces.
Tool-Body Assimilation Model Based on Body Babbling and Neurodynamical System
Directory of Open Access Journals (Sweden)
Kuniyuki Takahashi
2015-01-01
Full Text Available We propose the new method of tool use with a tool-body assimilation model based on body babbling and a neurodynamical system for robots to use tools. Almost all existing studies for robots to use tools require predetermined motions and tool features; the motion patterns are limited and the robots cannot use novel tools. Other studies fully search for all available parameters for novel tools, but this leads to massive amounts of calculations. To solve these problems, we took the following approach: we used a humanoid robot model to generate random motions based on human body babbling. These rich motion experiences were used to train recurrent and deep neural networks for modeling a body image. Tool features were self-organized in parametric bias, modulating the body image according to the tool in use. Finally, we designed a neural network for the robot to generate motion only from the target image. Experiments were conducted with multiple tools for manipulating a cylindrical target object. The results show that the tool-body assimilation model is capable of motion generation.
Lumped mass formulations for modeling flexible body systems
Rampalli, Rajiv
1989-01-01
The efforts of Mechanical Dynamics, Inc. in obtaining a general formulation for flexible bodies in a multibody setting are discussed. The efforts being supported by MDI, both in house and externally are summarized. The feasibility of using lumped mass approaches to modeling flexibility in a multibody dynamics context is examined. The kinematics and kinetics for a simple system consisting of two rigid bodies connected together by an elastic beam are developed in detail. Accuracy, efficiency and ease of use using this approach are some of the issues that are then looked at. The formulation is then generalized to a superelement containing several nodes and connecting several bodies. Superelement kinematics and kinetics equations are developed. The feasibility and effectiveness of the method is illustrated by the use of some examples illustrating phenomena common in the context of spacecraft motions.
Aeroservoelastic Modeling of Body Freedom Flutter for Control System Design
Ouellette, Jeffrey
2017-01-01
One of the most severe forms of coupling between aeroelasticity and flight dynamics is an instability called freedom flutter. The existing tools often assume relatively weak coupling, and are therefore unable to accurately model body freedom flutter. Because the existing tools were developed from traditional flutter analysis models, inconsistencies in the final models are not compatible with control system design tools. To resolve these issues, a number of small, but significant changes have been made to the existing approaches. A frequency domain transformation is used with the unsteady aerodynamics to ensure a more physically consistent stability axis rational function approximation of the unsteady aerodynamic model. The aerodynamic model is augmented with additional terms to account for limitations of the baseline unsteady aerodynamic model and to account for the gravity forces. An assumed modes method is used for the structural model to ensure a consistent definition of the aircraft states across the flight envelope. The X-56A stiff wing flight-test data were used to validate the current modeling approach. The flight-test data does not show body-freedom flutter, but does show coupling between the flight dynamics and the aeroelastic dynamics and the effects of the fuel weight.
Research on the Earth system multi-body force system dynamical model
Institute of Scientific and Technical Information of China (English)
CHEN; Xiaofei; BI; Siwen; WU; Fei; DONG; Qianlin
2006-01-01
This paper presents an overview of the binding force and freedom force of Earth system, and describes force moment to point and line and force system in the Earth system. It introduces the force theory of the Earth system multi-body force system from special or equivalent force system of Earth system mechanics, general force and no-power force of Earth system. Finally it describes the force and moment of nodes of Earth system and provides basic model for the research of the Earth system multi-body dynamics.
Inverse and forward dynamics: models of multi-body systems.
Otten, E
2003-01-01
Connected multi-body systems exhibit notoriously complex behaviour when driven by external and internal forces and torques. The problem of reconstructing the internal forces and/or torques from the movements and known external forces is called the 'inverse dynamics problem', whereas calculating motion from known internal forces and/or torques and resulting reaction forces is called the 'forward dynamics problem'. When stepping forward to cross the street, people use muscle forces that generate angular accelerations of their body segments and, by virtue of reaction forces from the street, a forward acceleration of the centre of mass of their body. Inverse dynamics calculations applied to a set of motion data from such an event can teach us how temporal patterns of joint torques were responsible for the observed motion. In forward dynamics calculations we may attempt to create motion from such temporal patterns, which is extremely difficult, because of the complex mechanical linkage along the chains forming the multi-body system. To understand, predict and sometimes control multi-body systems, we may want to have mathematical expressions for them. The Newton-Euler, Lagrangian and Featherstone approaches have their advantages and disadvantages. The simulation of collisions and the inclusion of muscle forces or other internal forces are discussed. Also, the possibility to perform a mixed inverse and forward dynamics calculation are dealt with. The use and limitations of these approaches form the conclusion. PMID:14561340
A New Approach and Analysis of Modeling the Human Body in RFID-Enabled Body-Centric Wireless Systems
Directory of Open Access Journals (Sweden)
Karoliina Koski
2014-01-01
Full Text Available Body-centric wireless systems demand wearable sensor and tag antennas that have robust impedance matching and provide enough gain for a reliable wireless communication link. In this paper, we discuss a novel and practical technique for the modeling of the human body in UHF RFID body-centric wireless systems. What makes this technique different is that we base the human model on measured far-field response from a reference tag attached to the human body. Hereby, the human body model accounts for the encountered human body effects on the tag performance. The on-body measurements are fast, which allows establishing a catalog of human body models for different tag locations and human subjects. Such catalog would provide a ready simulation model for a wide range of wireless body-centric applications in order to initiate a functional design. Our results demonstrate that the suggested modeling technique can be used in the design and optimization of wearable antennas for different real-case body-centric scenarios.
Human growth and body weight dynamics: an integrative systems model.
Rahmandad, Hazhir
2014-01-01
Quantifying human weight and height dynamics due to growth, aging, and energy balance can inform clinical practice and policy analysis. This paper presents the first mechanism-based model spanning full individual life and capturing changes in body weight, composition and height. Integrating previous empirical and modeling findings and validated against several additional empirical studies, the model replicates key trends in human growth including A) Changes in energy requirements from birth to old ages. B) Short and long-term dynamics of body weight and composition. C) Stunted growth with chronic malnutrition and potential for catch up growth. From obesity policy analysis to treating malnutrition and tracking growth trajectories, the model can address diverse policy questions. For example I find that even without further rise in obesity, the gap between healthy and actual Body Mass Indexes (BMIs) has embedded, for different population groups, a surplus of 14%-24% in energy intake which will be a source of significant inertia in obesity trends. In another analysis, energy deficit percentage needed to reduce BMI by one unit is found to be relatively constant across ages. Accompanying documented and freely available simulation model facilitates diverse applications customized to different sub-populations.
Articulated Lifting System Modeling Based on Dynamics of Flexible Multi-Body Systems
Institute of Scientific and Technical Information of China (English)
无
2007-01-01
In lifting sub-system of deep-sea mining system, spherical joint is used to connect lifting pipes to replace fixed joint. Based on Dynamics of Flexible Multi-body systems, the mechanics model of articulated lifting system is established. Under the four-grade and six-grade oceanic condition, dynamic responses of lifting system are simulated and experiment verified. The simulation results are consistent with experimental ones. The maximum moment of flexion is 322 kN-m on the first pipe under six-grade sea condition. It is seen that the articulated connection can reduce the moment of flexion. The bending deformation of pipe center is researched, and the maximum is 0.000479 m on the first pipe. Deformation has a little effect on the motion of system. It is feasible to analyze articulated lifting system by applying the theory of flexible multi-body dynamics. The articulated lifting system is obviously better than the fixed one.
Few-body systems in a shell-model approach
Energy Technology Data Exchange (ETDEWEB)
Toelle, Simon
2014-02-10
In this thesis, I introduce and compare an implementation of two different shell models for physical systems consisting of multiple identical bosons. In the main part, the shell model is used to study the energy spectra of bosons with contact interactions in a harmonic confinement as well as those of unconfined He clusters. The convergence of the shell-model results is investigated in detail as the size of the model space is increased. Furthermore, possible improvements such as the smearing of contact interactions or a unitary transformation of the potentials are utilised and assessed. Systems with up to twelve bosons are considered. Moreover, I test a procedure to determine scattering observables from the energy spectra of fermions in a harmonic confinement. Finally, the position and width of resonances are extracted from the dependence of the energy spectra on the oscillator length.
On the dynamics of chain systems. [applications in manipulator and human body models
Huston, R. L.; Passerello, C. E.
1974-01-01
A computer-oriented method for obtaining dynamical equations of motion for chain systems is presented. A chain system is defined as an arbitrarily assembled set of rigid bodies such that adjoining bodies have at least one common point and such that closed loops are not formed. The equations of motion are developed through the use of Lagrange's form of d'Alembert's principle. The method and procedure is illustrated with an elementary study of a tripod space manipulator. The method is designed for application with systems such as human body models, chains and cables, and dynamic finite-segment models.
Dynamic response to road roughness on a tractor-semitrailer system with driver body model
Institute of Scientific and Technical Information of China (English)
无
2002-01-01
A linear mass-spring system model of a tractor-semitrailer together with driver body parts and sprung seat is presented. Natural frequencies of the system are calculated and response of components in the system to road roughness is completed by means of computer simulation and power spectral density (PSD) approach in all of road conditions and loading cases. The results show that the severest situation of response of the system occurs when the road in rough condition and vehicle unladen. The most sensitive frequency to human body parts is around 0.9Hz, and model types of a human body seem to be not significant tothe response of a heavy tractor-semitrailer system, including to the response of the driver himself.
Dynamical model of binary asteroid systems through patched three-body problems
Ferrari, Fabio; Lavagna, Michèle; Howell, Kathleen C.
2016-08-01
The paper presents a strategy for trajectory design in the proximity of a binary asteroid pair. A novel patched approach has been used to design trajectories in the binary system, which is modeled by means of two different three-body systems. The model introduces some degrees of freedom with respect to a classical two-body approach and it is intended to model to higher accuracy the peculiar dynamical properties of such irregular and low gravity field bodies, while keeping the advantages of having a full analytical formulation and low computational cost required. The neighborhood of the asteroid couple is split into two regions of influence where two different three-body problems describe the dynamics of the spacecraft. These regions have been identified by introducing the concept of surface of equivalence (SOE), a three-dimensional surface that serves as boundary between the regions of influence of each dynamical model. A case of study is presented, in terms of potential scenario that may benefit of such an approach in solving its mission analysis. Cost-effective solutions to land a vehicle on the surface of a low gravity body are selected by generating Poincaré maps on the SOE, seeking intersections between stable and unstable manifolds of the two patched three-body systems.
Informatics System Design for the Management of Nutritional Supplementation in Body Modelling Sports
Directory of Open Access Journals (Sweden)
Dan MANESCU
2013-01-01
Full Text Available Issues regarding body modeling are debated. Facts regarding the nutrional oriented processes for body modeling are identified. The nutriments classes are presented and how the administration process is conducted based on several characteristics and which are the stages of succeeding these processes. An informatics system is designed for the management of nutritional supplementation in order to control the calories intake based on the intentisty of physical effort. The stages of development are presented, identifying optimization criteria for the security of the systems and its users.
The self-consistent field model for Fermi systems with account of three-body interactions
Directory of Open Access Journals (Sweden)
Yu.M. Poluektov
2015-12-01
Full Text Available On the basis of a microscopic model of self-consistent field, the thermodynamics of the many-particle Fermi system at finite temperatures with account of three-body interactions is built and the quasiparticle equations of motion are obtained. It is shown that the delta-like three-body interaction gives no contribution into the self-consistent field, and the description of three-body forces requires their nonlocality to be taken into account. The spatially uniform system is considered in detail, and on the basis of the developed microscopic approach general formulas are derived for the fermion's effective mass and the system's equation of state with account of contribution from three-body forces. The effective mass and pressure are numerically calculated for the potential of "semi-transparent sphere" type at zero temperature. Expansions of the effective mass and pressure in powers of density are obtained. It is shown that, with account of only pair forces, the interaction of repulsive character reduces the quasiparticle effective mass relative to the mass of a free particle, and the attractive interaction raises the effective mass. The question of thermodynamic stability of the Fermi system is considered and the three-body repulsive interaction is shown to extend the region of stability of the system with the interparticle pair attraction. The quasiparticle energy spectrum is calculated with account of three-body forces.
An Earth multi-body system elasticity and plasticity dynamics model
Institute of Scientific and Technical Information of China (English)
ZHANG Qingxian; BI Siwen; GONG Huili
2006-01-01
Research on the elasticity and plasticity dynamics of the Earth multi-body system, including the Earth multi-body system stratum-block's equivalent inertia force system and generalized inertia force, the Earth multi-body system stratum-block's equivalent inertia force system expressed with partial velocity and partial palstance, and Earth multi-body system generalized inertia force expressed with partial velocity and partial palstance. This research provides a theoretical foundation for further investigation of Earth multi-body dynamics.
A novel body motion model based personal dead-reckoning system
Xiang, Zhiyu; Qi, Baozhen; Wang, Jiafeng
2011-10-01
This paper presents a novel human body motion model based dead reckoning approach. After brief description of system overview, a new body motion model is given based on the inherent relationship between step frequency and step length existed in two common motion patterns: walking and running. The parameter calibration of the model is given as well. Upon receiving the data from sensors, step frequency is first computed by detecting the periodic changing of linear acceleration in vertical axis, and then the real-time footstep length can be obtained according to the proposed motion model. Angular velocity measurement produced by vertical gyroscope is filtered and integrated by Kalman filter to obtain motion direction change. With movement distance and direction in hand, dead-reckoning can be easily carried out. Experimental results based on real data acquired under different motion patterns show the promising performance of the system.
DAE for Frictional Contact Modeling of Constrained Multi-Flexible Body Systems
Institute of Scientific and Technical Information of China (English)
Ray P.S.Han; S. G. Mao
2004-01-01
A general formulation for modeling frictional contact interactions in a constrained multi-flexible body system is outlined in this paper. The governing differential-algebraic equations (DAE) for the constrained motion contains not only a frictional term but also, the unknown contact conditions. These contact conditions are characterized by a set of nonlinear complementarity equations. To demonstrate the model, a falling-spinning beam impacting a rough elastic ground with damping is solved and comparison with Stewart-Trinkles' results provided.
Qianxiang, Zhou
2012-07-01
It is very important to clarify the geometric characteristic of human body segment and constitute analysis model for ergonomic design and the application of ergonomic virtual human. The typical anthropometric data of 1122 Chinese men aged 20-35 years were collected using three-dimensional laser scanner for human body. According to the correlation between different parameters, curve fitting were made between seven trunk parameters and ten body parameters with the SPSS 16.0 software. It can be concluded that hip circumference and shoulder breadth are the most important parameters in the models and the two parameters have high correlation with the others parameters of human body. By comparison with the conventional regressive curves, the present regression equation with the seven trunk parameters is more accurate to forecast the geometric dimensions of head, neck, height and the four limbs with high precision. Therefore, it is greatly valuable for ergonomic design and analysis of man-machine system.This result will be very useful to astronaut body model analysis and application.
Trajectory refinement of three-body orbits in the real solar system model
Dei Tos, Diogene A.; Topputo, Francesco
2017-04-01
In this paper, an automatic algorithm for the correction of orbits in the real solar system model is described. The differential equations governing the dynamics of a massless particle in the n-body problem are written as perturbation of the circular restricted three-body problem in a non-uniformly rotating, pulsating frame by using a Lagrangian formalism. The refinement is carried out by means of a modified multiple shooting technique, and the problem is solved for a finite number of trajectory states at several time instants. The analysis involves computing the dynamical substitutes of the collinear points, as well as several Lagrange point orbits, for the Sun-Earth, Sun-Jupiter, and Earth-Moon gravitational systems.
Three-dimensional modeling of supine human and transport system under whole-body vibration.
Wang, Yang; Rahmatalla, Salam
2013-06-01
The development of predictive computer human models in whole-body vibration has shown some success in predicting simple types of motion, mostly for seated positions and in the uniaxial vertical direction. The literature revealed only a handful of papers that tackled supine human modeling in response to vertical vibration. The objective of this work is to develop a predictive, multibody, three-dimensional human model to simulate the supine human and underlying transport system in response to multidirectional whole-body vibration. A three-dimensional dynamic model of a supine human and its underlying transport system is presented in this work to predict supine-human biodynamic response under three-dimensional input random whole-body vibration. The proposed supine-human model consists of three interconnected segments representing the head, torso-arms, and pelvis-legs. The segments are connected via rotational and translational joints that have spring-damper components simulating the three-dimensional muscles and tissuelike connecting elements in the three x, y, and z directions. Two types of transport systems are considered in this work, a rigid support and a long spinal board attached to a standard military litter. The contact surfaces between the supine human and the underlying transport system are modeled using spring-damper components. Eight healthy supine human subjects were tested under combined-axis vibration files with a magnitude of 0.5 m/s2 (rms) and a frequency content of 0.5-16 Hz. The data from seven subjects were used in parameter identification for the dynamic model using optimization schemes in the frequency domain that minimize the differences between the magnitude and phase of the predicted and experimental transmissibility. The predicted accelerations in the time and frequency domains were comparable to those gathered from experiments under different anthropometric, input vibration, and transport conditions under investigation. Based on the
Bhaskaran, Santosh; Dixit, Jyotsana; Sahasrabuddhe, Ajit; Vidyasagar, Pandit B
2011-01-01
Spaceflights and clinostats have been used extensively to study the effects of microgravity on various biological systems ranging from microbes to plants. Similarly hypergravity studies have been carried out using centrifuges where growth retardation has been observed. However, no studies have been carried out yet on how the gravity of astronomical bodies, e.g. Moon having 1/6th the gravity of Earth, affects biological systems. Such studies are important with missions to Moon and Mars to be carried out in future. Also, a comparative study to see the effects of gravity that exists on astronomical bodies such as Moon, Mars and Jupiter on any organism using simulation have not been reported so far. This paper discusses the effects of modelled gravity on the growth of Vibrio harveyi using the clinostat-centrifuge system designed and developed in-house. Results showed that though growth as measured by optical density was significantly higher for simulated microgravity and lunar and Martian gravities, there was no ...
Computational human body models
Wismans, J.S.H.M.; Happee, R.; Dommelen, J.A.W. van
2005-01-01
Computational human body models are widely used for automotive crashsafety research and design and as such have significantly contributed to a reduction of traffic injuries and fatalities. Currently crash simulations are mainly performed using models based on crash-dummies. However crash dummies dif
KEY TECHNIQUES OF MULTI-BODY MODELING OF OCCUPANT RESTRAINT SYSTEM OF VEHICLE SIDE IMPACT
Institute of Scientific and Technical Information of China (English)
ZHANG Junyuan; ZHANG Min; DING Rufang; QIU Shaobo; ZHANG Yu; LI Hongjian
2006-01-01
Based on multi-body dynamics, the simulation models of auto-side structures and occupant's dynamic responses are set up, using the occupant injury simulation software MADYMO3D. These models include auto-body structure, impact barrier, seat and dummy. Definitions of multi-body and joints and dynamics properties of joints based on FE combination models, of model setup are introduced. Kelvin element of MADYMO is introduced to show the force action between non-adjoining rigid bodies, too. Then all examples of the methods mentioned are given. By the comparison of simulation and real test, the contract curves between simulation and real test for main structures and biology mechanics properties of dummy are obtained. The result shows the accuracy and validity of the models.
Electrostatically Embedded Many-Body Expansion for Neutral and Charged Metalloenzyme Model Systems.
Kurbanov, Elbek K; Leverentz, Hannah R; Truhlar, Donald G; Amin, Elizabeth A
2012-01-10
The electrostatically embedded many-body (EE-MB) method has proven accurate for calculating cohesive and conformational energies in clusters, and it has recently been extended to obtain bond dissociation energies for metal-ligand bonds in positively charged inorganic coordination complexes. In the present paper, we present four key guidelines that maximize the accuracy and efficiency of EE-MB calculations for metal centers. Then, following these guidelines, we show that the EE-MB method can also perform well for bond dissociation energies in a variety of neutral and negatively charged inorganic coordination systems representing metalloenzyme active sites, including a model of the catalytic site of the zinc-bearing anthrax toxin lethal factor, a popular target for drug development. In particular, we find that the electrostatically embedded three-body (EE-3B) method is able to reproduce conventionally calculated bond-breaking energies in a series of pentacoordinate and hexacoordinate zinc-containing systems with an average absolute error (averaged over 25 cases) of only 0.98 kcal/mol.
Energy Technology Data Exchange (ETDEWEB)
Kumekawa, Y.; Miura, Y.; Takasugi, S. [Geothermal Energy Research and Development Co. Ltd., Tokyo (Japan); Arai, E. [Metal Mining Agency of Japan, Tokyo (Japan)
1996-05-01
An examination was made by a model analysis on sensitivity and the like against a resistive anomalous body, in connection with an electromagnetic tomography system with surface earthquake sources and underground receiver arrangements. A resistivity model was of a three-dimensional structure, and built with a 5 ohm{center_dot}m low resistivity anomalous body assembled in a 100 ohm{center_dot}m homogeneous medium. As a result of the examination, it was shown that the size limitation of an analyzable anomalous body was 50{times}50{times}20m at a frequency of 8 to 10kHz and that a system with high precision in a high frequency range was necessary. The examination of effects under a shallow anomalous body revealed, for example, that the fluctuation of a low frequency response was large compared with a deep anomalous body and that, where a second anomalous body existed under it, the effect also appeared with a surface earthquake source positioned in the opposite side from the anomalous body. The examination of effects under the three dimensional structure revealed, for example, that a remarkable change appeared in the data with the change in the inclined angle of the transmission line against the strike of the anomalous body. 4 refs., 7 figs.
Modeling gunshot bruises in soft body armor with an adaptive fuzzy system.
Lee, Ian; Kosko, Bart; Anderson, W French
2005-12-01
Gunshots produce bruise patterns on persons who wear soft body armor when shot even though the armor stops the bullets. An adaptive fuzzy system modeled these bruise patterns based on the depth and width of the deformed armor given a projectile's mass and momentum. The fuzzy system used rules with sinc-shaped if-part fuzzy sets and was robust against random rule pruning: Median and mean test errors remained low even after removing up to one fifth of the rules. Handguns shot different caliber bullets at armor that had a 10%-ordnance gelatin backing. The gelatin blocks were tissue simulants. The gunshot data tuned the additive fuzzy function approximator. The fuzzy system's conditional variance V[Y/X = x] described the second-order uncertainty of the function approximation. Handguns with different barrel lengths shot bullets over a fixed distance at armor-clad gelatin blocks that we made with Type 250 A Ordnance Gelatin. The bullet-armor experiments found that a bullet's weight and momentum correlated with the depth of its impact on armor-clad gelatin (R2 = 0.881 and p-value baseball impacts compared well to bullet-armor impacts for large-caliber handguns. A baseball's momentum correlated with its impact depth in putty (R2 = 0.93 and p-value Baseball impact depths were comparable to bullet-armor impact depths: Getting shot with a .22 caliber bullet when wearing soft body armor resembles getting hit in the chest with a 40-mph baseball. Getting shot with a .45 caliber bullet resembles getting hit with a 90-mph baseball.
Schmutzer, E
2005-01-01
In a previous paper we treated within the framework of our Projective Unified Field Theory (Schmutzer 2004, Schmutzer 2005a) the 2-body system (e.g. earth-moon system) with a rotating central body in a rather abstract manner. Here a concrete model of the transfer of angular momentum from the rotating central body to the orbital motion of the whole 2-body system is presented, where particularly the transfer is caused by the inhomogeneous gravitational force of the moon acting on the oceanic waters of the earth, being modeled by a spherical shell around the solid earth. The theory is numerically tested. Key words: transfer of angular momentum from earth to moon, action of the gravitational force of the moon on the waters of the earth.
Institute of Scientific and Technical Information of China (English)
GONG Yan-Jun; WU Zhen-Sen; WU Jia-Ji
2009-01-01
We present an analytical model of Doppler spectra in backscattering from arbitrary rough convex bodies of revolution rotating around their axes in the global Cartesian coordinate system. This analytical model is applied to analyse Doppler spectra in backscatter from two cones and two cylinders, as well as two ellipsoids of revolution. We numerically analyse the influences of attitude and geometry size of objects on Doppler spectra. The analytical model can give contribution of the surface roughness, attitude and geometry size of convex bodies of revolution to Doppler spectra and may contribute to laser Doppler velocimetry as well as ladar applications.
Energy Technology Data Exchange (ETDEWEB)
Rivasseau, Vincent [Paris-Sud Univ. Orsay (France). Laboratoire de Physique Theorique; Seiringer, Robert [McGill Univ., Montreal, QC (Canada). Dept. of Mathematics and Statistics; Solovej, Jan Philip [Copenhagen Univ. (Denmark). Dept. of Mathematics; Spencer, Thomas [Institute for Advanced Study, Princeton, NJ (United States). School of Mathematics
2012-11-01
The book is based on the lectures given at the CIME school ''Quantum many body systems'' held in the summer of 2010. It provides a tutorial introduction to recent advances in the mathematics of interacting systems, written by four leading experts in the field: V. Rivasseau illustrates the applications of constructive Quantum Field Theory to 2D interacting electrons and their relation to quantum gravity; R. Seiringer describes a proof of Bose-Einstein condensation in the Gross-Pitaevski limit and explains the effects of rotating traps and the emergence of lattices of quantized vortices; J.-P. Solovej gives an introduction to the theory of quantum Coulomb systems and to the functional analytic methods used to prove their thermodynamic stability; finally, T. Spencer explains the supersymmetric approach to Anderson localization and its relation to the theory of random matrices. All the lectures are characterized by their mathematical rigor combined with physical insights.
Hyperspherical three-body model calculation for the bound $^{1,3}$S-states of Coulombic systems
Khan, Md Abdul
2014-01-01
In this paper, hyperspherical three-body model formalism has been applied for the calculation energies of the low-lying bound $^{1,3}$S (L=0)-states of neutral helium and helium like Coulombic three-body systems having nuclear charge (Z) in the range Z=2 to Z=92. The calculation of the coupling potential matrix elements of the two-body potentials has been simplified by the introduction of Raynal-Revai Coefficients (RRC). The three-body wave function in the Schr\\H{o}dinger equation when expanded in terms of hyperpherical harmonics (HH), leads to an infinite set of coupled differential equation (CDE). For practical reason the infinite set of CDE is truncated to a finite set and are solved by an exact numerical method known as renormalized Numerov method (RNM) to get the energy solution (E). The calculated energy is compared with the ones of the literature.
Ranavolo, Alberto; Don, Romildo; Draicchio, Francesco; Bartolo, Michelangelo; Serrao, Mariano; Padua, Luca; Cipolla, Gianfranco; Pierelli, Francesco; Iavicoli, Sergio; Sandrini, Giorgio
2013-03-01
The aims of this study were to develop a kinematic model of the spine, seen as a continuous deformable body and to identify the smallest set of surface markers allowing adequate measurements of spine motion. The spine is widely considered as a rigid body or as a kinematic chain made up of a smaller number of segments, thereby introducing an approximation. It would be useful to have at our disposal a technique ensuring accurate and repeatable measurement of the shape of the whole spine. Ten healthy subjects underwent a whole-spine radiographic assessment and, simultaneously, an optoelectronic recording. Polynomial interpolations of the vertebral centroids, of the whole set of markers were performed. The similarity of the resulting curves was assessed. Our findings indicate that spine shape can be reproduced by 5th order polynomial interpolation. The best approximating curves are obtained from either 10- or 9-marker sets. Sagittal angles are systematically underestimated.
Lossec, M.; Multon, B.; Ben Ahmed, H.; Goupil, C.
2010-10-01
This paper focuses on the production of electricity using a thermoelectric generator placed on the human body connected to a dc-dc converter. The small difference in temperature between the hot heat source (e.g. the human body, Tb = 37 °C) and the cold heat source (e.g. ambient air, Ta = 22 °C), associated with a poor quality thermal coupling (mainly with the cold source), leads to a very low temperature gradient at the thermoelectric generator terminals and hence low productivity. Under these use conditions, the present article proposes an analysis of various ways to improve productivity given a surface capture system. Furthermore, we demonstrated, in this particular context, that maximizing the recovered electric power proves to be a different problem from that of maximizing efficiency, e.g. the figure of merit Z. We therefore define a new factor ZE, depending on the physical characteristics of thermoelectric materials, that maximizes electric power in the particular case where the thermal coupling is poor. Finally, this study highlights the benefit of sub-optimization of the power extracted from the thermoelectric generator to further improve efficiency of the overall system. We show that, given the conversion efficiency of the dc-dc converter, the maximum power point of the overall system is no more reached when the output voltage of the thermoelectric generator is equal to half of its electromotive force.
Schaller, S; Willmann, S; Lippert, J; Schaupp, L; Pieber, T R; Schuppert, A; Eissing, T
2013-01-01
Models of glucose metabolism are a valuable tool for fundamental and applied medical research in diabetes. Use cases range from pharmaceutical target selection to automatic blood glucose control. Standard compartmental models represent little biological detail, which hampers the integration of multiscale data and confines predictive capabilities. We developed a detailed, generic physiologically based whole-body model of the glucose-insulin-glucagon regulatory system, reflecting detailed physiological properties of healthy populations and type 1 diabetes individuals expressed in the respective parameterizations. The model features a detailed representation of absorption models for oral glucose, subcutaneous insulin and glucagon, and an insulin receptor model relating pharmacokinetic properties to pharmacodynamic effects. Model development and validation is based on literature data. The quality of predictions is high and captures relevant observed inter- and intra-individual variability. In the generic form, the model can be applied to the development and validation of novel diabetes treatment strategies. PMID:23945606
Suzuki, Naoki; Hattori, Asaki; Hashizume, Makoto
2016-01-01
We constructed a four dimensional human model that is able to visualize the structure of a whole human body, including the inner structures, in real-time to allow us to analyze human dynamic changes in the temporal, spatial and quantitative domains. To verify whether our model was generating changes according to real human body dynamics, we measured a participant's skin expansion and compared it to that of the model conducted under the same body movement. We also made a contribution to the field of orthopedics, as we were able to devise a display method that enables the observer to more easily observe the changes made in the complex skeletal muscle system during body movements, which in the past were difficult to visualize.
Berry, D.P.; Buckley, F.; Dillon, P.; Evans, R.D.; Rath, M.; Veerkamp, R.F.
2003-01-01
(Co)variance components for milk yield, body condition score (BCS), body weight (BW), BCS change and BW change over different herd-year mean milk yields (HMY) and nutritional environments (concentrate feeding level, grazing severity and silage quality) were estimated using a random regression model.
Organoid-on-a-chip and body-on-a-chip systems for drug screening and disease modeling.
Skardal, Aleksander; Shupe, Thomas; Atala, Anthony
2016-09-01
In recent years, advances in tissue engineering and microfabrication technologies have enabled rapid growth in the areas of in vitro organoid development as well as organoid-on-a-chip platforms. These 3D model systems often are able to mimic human physiology more accurately than traditional 2D cultures and animal models. In this review, we describe the progress that has been made to generate organ-on-a-chip platforms and, more recently, more complex multi-organoid body-on-a-chip platforms and their applications. Importantly, these systems have the potential to dramatically impact biomedical applications in the areas of drug development, drug and toxicology screening, disease modeling, and the emerging area of personalized precision medicine.
Directory of Open Access Journals (Sweden)
Stephan Fuchs
2017-03-01
Full Text Available An accurate budget of substance emissions is fundamental for protecting freshwater resources. In this context, the European Union asks all member states to report an emission inventory of substances for river basins. The river basin management system MoRE (Modeling of Regionalized Emissions was developed as a flexible open-source instrument which is able to model pathway-specific emissions and river loads on a catchment scale. As the reporting tool for the Federal Republic of Germany, MoRE is used to model annual emissions of nutrients, heavy metals, micropollutants like polycyclic aromatic hydrocarbons (PAH, Bis(2-ethylhexylphthalate (DEHP, and certain pharmaceuticals. Observed loads at gauging stations are used to validate the calculated emissions. In addition to its balancing capabilities, MoRE can consider different variants of input data and quantification approaches, in order to improve the robustness of different modeling approaches and to evaluate the quality of different input data. No programming skills are required to set up and run the model. Due to its flexible modeling base, the effect of reduction measures can be assessed. Within strategic planning processes, this is relevant for the allocation of investments or the implementation of specific measures to reduce the overall pollutant emissions into surface water bodies and therefore to meet the requirements of water policy.
Jefferies-Sewell, K; Chamberlain, SR; Fineberg, NA; Laws, KR
2017-01-01
Background Body dysmorphic disorder (BDD) is a debilitating disorder, characterised by obsessions and compulsions relating specifically to perceived appearance, newly classified within the DSM-5 Obsessive-Compulsive and Related Disorders grouping. Until now, little research has been conducted into the cognitive profile of this disorder. Materials and Methods Participants with BDD (n=12) and healthy controls (n=16) were tested using a computerised neurocognitive battery investigating attentional set-shifting (Intra/Extra Dimensional Set Shift Task), decision-making (Cambridge Gamble Task), motor response-inhibition (Stop-Signal Reaction Time Task) and affective processing (Affective Go-No Go Task). The groups were matched for age, IQ and education. Results In comparison to controls, patients with BDD showed significantly impaired attentional set shifting, abnormal decision-making, impaired response inhibition and greater omission and commission errors on the emotional processing task. Conclusions Despite the modest sample size, our results showed that individuals with BDD performed poorly compared to healthy controls on tests of cognitive flexibility, reward and motor impulsivity and affective processing. Results from separate studies in OCD patients suggest similar cognitive dysfunction. Therefore, these findings are consistent with the re-classification of BDD alongside OCD. These data also hint at additional areas of decision-making abnormalities that might contribute specifically to the psychopathology of BDD. PMID:27899165
Mathematical human body modelling for impact loading
Happee, R.; Morsink, P.L.J.; Wismans, J.S.H.M.
1999-01-01
Mathematical modelling of the human body is widely used for automotive crash safety research and design. Simulations have contributed to a reduction of injury numbers by optimisation of vehicle structures and restraint systems. Currently such simulations are largely performed using occupant models b
Modeling Forces on the Human Body.
Pagonis, Vasilis; Drake, Russel; Morgan, Michael; Peters, Todd; Riddle, Chris; Rollins, Karen
1999-01-01
Presents five models of the human body as a mechanical system which can be used in introductory physics courses: human arms as levers, humans falling from small heights, a model of the human back, collisions during football, and the rotating gymnast. Gives ideas for discussions and activities, including Interactive Physics (TM) simulations. (WRM)
A covariant model of the electromagnetic current for the study of two-body scalar systems
Acero, M A; Sandoval, C E; Sanctis, Maurizio De; Sandoval, Carlos E.
2005-01-01
We present a procedure to derive a covariant electromagnetic current operator for a system made up by two scalars constituents. Using different wave functions we fitted their parameters to the experimental data of the pion form factor, obtainig great discrepancy at low momentum transfer. Introducing the Vector Meson Dominance corrective factor, we obtained a better fit to the data.
Analysis and modeling of error of spiral bevel gear grinder based on multi-body system theory
Institute of Scientific and Technical Information of China (English)
CHEN Shu-han; YAN Hong-zhi; MING Xing-zu
2008-01-01
Six-axis numerical control spiral bevel gear grinder was taken as the object, multi-body system theory and Denavit-Hartenberg homogeneous transformed matrix (HTM) were utilized to establish the grinder synthesis error model, and the validity of model was confirmed by the experiment. Additionally, in grinding wheel tool point coordinate system, the errors of six degrees of freedom were simulated when the grinding wheel revolving around C-axis, moving along X-axis and Y-axis. The influence of these six errors on teeth space, helix angle, pitch, teeth profile was discussed. The simulation results show that the angle error is in the range from -0.1484 rad to -0.2419 rad when grinding wheel moving along X, Y-axis; the translation error is in the range from 0.8660 μm to 3.6053 μm when grinding wheel moving along X-axis. These angle and translation errors have a great influence on the helix angle, pitch, teeth thickness and tooth socket.
Composition of Solar System Small Bodies
Vernazza, Pierre
2016-01-01
The aim of the chapter is to summarize our understanding of the compositional distribution across the different reservoirs of small bodies (main belt asteroids, giant planet trojans, irregular satellites of the giant planets, TNOs, comets). We then use this information to i) discuss current dynamical models (Nice and Grand Tack models), ii) mention possible caveats in these models if any, and iii) draw a preliminary version of the primordial compositional gradient across the solar system before planetary migrations occured. Note that the composition of both planetary satellites (the regular ones) and that of the transient populations (NEOs, centaurs) is not discussed here. We strictly focus on the composition of the main reservoirs of small bodies. The manuscript's objective is to provide a global and synthetic view of small bodies' compositions rather than a very detailed one, for specific reviews regarding the composition of small bodies, see papers by Burbine (2014) for asteroids, Emery et al. (2015) for J...
Mechanism test bed. Flexible body model report
Compton, Jimmy
1991-01-01
The Space Station Mechanism Test Bed is a six degree-of-freedom motion simulation facility used to evaluate docking and berthing hardware mechanisms. A generalized rigid body math model was developed which allowed the computation of vehicle relative motion in six DOF due to forces and moments from mechanism contact, attitude control systems, and gravity. No vehicle size limitations were imposed in the model. The equations of motion were based on Hill's equations for translational motion with respect to a nominal circular earth orbit and Newton-Euler equations for rotational motion. This rigid body model and supporting software were being refined.
Energy Technology Data Exchange (ETDEWEB)
Kumekawa, Y.; Miura, Y.; Takasugi, S. [GERD Geothermal Energy Research and Development Co. Ltd., Tokyo (Japan); Arai, E. [Metal Mining Agency of Japan, Tokyo (Japan)
1997-05-27
A model analysis was used to investigate sensitivity of a two-dimensional structure on a resistivity anomalous body by using an electromagnetic tomography system. The resistivity model handled a three-dimensional structure. The model was prepared as a pseudo two-dimensional model in which a low resistivity anomalous body with 1 ohm-m was incorporated that has a basic length of 1000 m in the Y-direction in a homogenous medium having 100 ohm-m. As a result of the analysis, the following matters were elucidated: if a low resistivity anomalous body is present in a shallow subsurface, its impact starts appearing from lower frequencies than when the anomalous body exists only at a greater depth; if a high resistivity anomalous body exists, the detection sensitivity is lower than for the low resistivity anomalous body, but the analysis would be possible by using the phase because the phase has made a greater change; the source TxZ shows a change from lower frequencies than for the source TxX, and the amount of change is greater, hence the detection sensitivity on an anomalous body may be said higher with the source TxZ; however, for the anomalous body in shallow subsurface, the source TxX is more effective since it is not subjected to a too great impact at a greater depth. 5 refs., 7 figs.
An Exactly Solvable Many-Body Model
Zettili, Nouredine; Boukahil, Abdelkrim
2012-03-01
We deal here with the construction of a simple many-body model that can be solved exactly. This model serves as a tool for testing the validity and accuracy of many-body approximation methods, most notably those encountered in nuclear theory. The model consists of a system of two distinguishable, one-dimensional sets fermions interacting via a schematic two-body force. We construct the Hamiltonian of the model by means of vector operators that satisfy a Lie algebra and which are the generators of an SO(2,1) group. The Hamiltonian depends on an adjustable parameter which regulates the strength of the two-body interaction. The size of the Hamiltonian's matrix is rendered finite by means of a built-in symmetry: the Hamiltonian is represented by a five-diagonal square matrix of finite size. The energy spectrum of the model is obtained by diagonalizing this matrix. The energy eigenvalues obtained from this diagonalization are exact, for we don't need to resort to any approximation in the diagonalization. This model offers a rich and flexible platform for testing quantitatively the various many-body approximation methods especially those that deal with nuclear collective motion.
Aziz Ayyad, Ezzat
A mathematical representation is sought to model the behavior of a portable pneumatic foam bladder designed to mitigate the effects of human exposure to shock and whole body random vibration. Fluid Dynamics principles are used to derive the analytic differential equations used for the physical equations Model. Additionally, combination of Wiener and Hammerstein block oriented representation techniques have been selected to create system identification (SID) block oriented models. A number of algorithms have been iterated to obtain numerical solutions for the system of equations which was found to be coupled and non-linear, with no analytic closed form solution. The purpose is to be able to predict the response of such system due to random vibrations and shock within reasonable margin of error. The constructed models were found to be accurate within accepted confidence level. Beside the analytic set of physical equations model representation, a linear SID model was selected to take advantage of the available vast amount of mathematical tools available to further analyze and redesign the bladder as a dynamic system. Measured field-test and lab test data have been collected from several helicopter and land terrain vehicle experiments. Numerous excitation and response acceleration measurement records were collected and used to prove the agreement with predictions. The estimation of two selected models were later applied to standard metrics in the frequency domain realization and compared with measurement responses. The collected test records are obtained from measured data at the US Army fields and facilities and at UNLV-CMEST environmental lab. The emerged models have been validated for conformity with actual accelerometer measurement responses and found within accepted error tolerance that is in both time and frequency domains. Further, standard metrics have been used to further confirm the confidence in the validation results. When comparing model prediction with
Directory of Open Access Journals (Sweden)
Girondel Vincent
2006-01-01
Full Text Available This paper describes a system for human body analysis (segmentation, tracking, face/hands localisation, posture recognition from a single view that is fast and completely automatic. The system first extracts low-level data and uses part of the data for high-level interpretation. It can detect and track several persons even if they merge or are completely occluded by another person from the camera's point of view. For the high-level interpretation step, static posture recognition is performed using a belief theory-based classifier. The belief theory is considered here as a new approach for performing posture recognition and classification using imprecise and/or conflicting data. Four different static postures are considered: standing, sitting, squatting, and lying. The aim of this paper is to give a global view and an evaluation of the performances of the entire system and to describe in detail each of its processing steps, whereas our previous publications focused on a single part of the system. The efficiency and the limits of the system have been highlighted on a database of more than fifty video sequences where a dozen different individuals appear. This system allows real-time processing and aims at monitoring elderly people in video surveillance applications or at the mixing of real and virtual worlds in ambient intelligence systems.
Dirnbeck, Matthew R.
Biological systems pose a challenge both for learners and teachers because they are complex systems mediated by feedback loops; networks of cause-effect relationships; and non-linear, hierarchical, and emergent properties. Teachers and scientists routinely use models to communicate ideas about complex systems. Model-based pedagogies engage students in model construction as a means of practicing higher-order reasoning skills. One such modeling paradigm describes systems in terms of their structures, behaviors, and functions (SBF). The SBF framework is a simple modeling language that has been used to teach about complex biological systems. Here, we used student-generated SBF models to assess students' causal reasoning in the context of a novel biological problem on an exam. We compared students' performance on the modeling problem, their performance on a set of knowledge/comprehension questions, and their performance on a set of scientific reasoning questions. We found that students who performed well on knowledge and understanding questions also constructed more networked, higher quality models. Previous studies have shown that learners' mental maps increase in complexity with increased expertise. We wanted to investigate if biology students with varying levels of training in biology showed a similar pattern when constructing system models. In a pilot study, we administered the same modeling problem to two additional groups of students: 1) an animal physiology course for students pursuing a major in biology (n=37) and 2) an exercise physiology course for non-majors (n=27). We found that there was no significant difference in model organization across the three student populations, but there was a significant difference in the ability to represent function between the three populations. Between the three groups the non-majors had the lowest function scores, the introductory majors had the middle function scores, and the upper division majors had the highest function
Few-body models for nuclear astrophysics
Energy Technology Data Exchange (ETDEWEB)
Descouvemont, P., E-mail: pdesc@ulb.ac.be [Physique Nucléaire Théorique et Physique Mathématique, C.P. 229, Université Libre de Bruxelles (ULB), B 1050 Brussels (Belgium); Baye, D., E-mail: dbaye@ulb.ac.be [Physique Nucléaire Théorique et Physique Mathématique, C.P. 229, Université Libre de Bruxelles (ULB), B 1050 Brussels (Belgium); Physique Quantique, C.P. 165/82, Université Libre de Bruxelles (ULB), B 1050 Brussels (Belgium); Suzuki, Y., E-mail: suzuki@nt.sc.niigata-u.ac.jp [Department of Physics, Niigata University, Niigata 950-2181 (Japan); RIKEN Nishina Center, Wako 351-0198 (Japan); Aoyama, S., E-mail: aoyama@cc.niigata-u.ac.jp [Center for Academic Information Service, Niigata University, Niigata 950-2181 (Japan); Arai, K., E-mail: arai@nagaoka-ct.ac.jp [Division of General Education, Nagaoka National College of Technology, 888 Nishikatakai, Nagaoka, Niigata 940-8532 (Japan)
2014-04-15
We present applications of microscopic models to nuclear reactions of astrophysical interest, and we essentially focus on few-body systems. The calculation of radiative-capture and transfer cross sections is outlined, and we discuss the corresponding reaction rates. Microscopic theories are briefly presented, and we emphasize on the matrix elements of four-body systems. The microscopic extension of the R-matrix theory to nuclear reactions is described. Applications to the {sup 2}H(d, γ){sup 4}He, {sup 2}H(d, p){sup 3}H and {sup 2}H(d, n){sup 3}He reactions are presented. We show the importance of the tensor force to reproduce the low-energy behaviour of the cross sections.
Few-body models for nuclear astrophysics
Directory of Open Access Journals (Sweden)
P. Descouvemont
2014-02-01
Full Text Available We present applications of microscopic models to nuclear reactions of astrophysical interest, and we essentially focus on few-body systems. The calculation of radiative-capture and transfer cross sections is outlined, and we discuss the corresponding reaction rates. Microscopic theories are briefly presented, and we emphasize on the matrix elements of four-body systems. The microscopic extension of the R-matrix theory to nuclear reactions is described. Applications to the 2H(d, γ4He, 2H(d, p3H and 2H(d, n3He reactions are presented. We show the importance of the tensor force to reproduce the low-energy behaviour of the cross sections.
Musculoskeletal modelling of low-frequency whole-body vibrations
DEFF Research Database (Denmark)
Rasmussen, John; Andersen, Michael Skipper
2012-01-01
This paper presents a musculoskeletal model for assessment of the effect of low-frequency whole-body vibrations on the human body. It is a basic assumption behind the model that the vibrations are slow enough to allow the central nervous system to respond to them in terms of muscle activations...
Shimamoto, Takuya; Laakso, Ilkka; Hirata, Akimasa
2015-01-07
The in-situ electric field of an adult male model in different postures is evaluated for exposure to the magnetic field leaked from a wireless power transfer system in an electrical vehicle. The transfer system is located below the centre of the vehicle body and the transferred power and frequency are 7 kW and 85 kHz, respectively. The in-situ electric field is evaluated for a human model (i) crouching near the vehicle, (ii) lying on the ground with or without his arm stretched, (iii) sitting in the driver's seat, and (iv) standing on a transmitting coil without a receiving coil. In each scenario, the maximum in-situ electric fields are lower than the allowable limit prescribed by international guidelines, although the local magnetic field strength in regions of the human body is higher than the allowable external magnetic field strength. The highest in-situ electric field is observed when the human body model is placed on the ground with his arm extended toward the coils, because of a higher magnetic field around the arm.
High School Students' Understanding of the Human Body System
Assaraf, Orit Ben-Zvi; Dodick, Jeff; Tripto, Jaklin
2013-01-01
In this study, 120 tenth-grade students from 8 schools were examined to determine the extent of their ability to perceive the human body as a system after completing the first stage in their biology curriculum--"The human body, emphasizing homeostasis". The students' systems thinking was analyzed according to the STH thinking model, which roughly…
Kanematsu, Nobuyuki; Inaniwa, Taku; Nakao, Minoru
2016-07-01
In the conventional procedure for accurate Monte Carlo simulation of radiotherapy, a CT number given to each pixel of a patient image is directly converted to mass density and elemental composition using their respective functions that have been calibrated specifically for the relevant x-ray CT system. We propose an alternative approach that is a conversion in two steps: the first from CT number to density and the second from density to composition. Based on the latest compilation of standard tissues for reference adult male and female phantoms, we sorted the standard tissues into groups by mass density and defined the representative tissues by averaging the material properties per group. With these representative tissues, we formulated polyline relations between mass density and each of the following; electron density, stopping-power ratio and elemental densities. We also revised a procedure of stoichiometric calibration for CT-number conversion and demonstrated the two-step conversion method for a theoretically emulated CT system with hypothetical 80 keV photons. For the standard tissues, high correlation was generally observed between mass density and the other densities excluding those of C and O for the light spongiosa tissues between 1.0 g cm-3 and 1.1 g cm-3 occupying 1% of the human body mass. The polylines fitted to the dominant tissues were generally consistent with similar formulations in the literature. The two-step conversion procedure was demonstrated to be practical and will potentially facilitate Monte Carlo simulation for treatment planning and for retrospective analysis of treatment plans with little impact on the management of planning CT systems.
Radio channel modeling in body area networks
An, L.; Bentum, M.J.; Meijerink, A.; Scanlon, W.G.
2010-01-01
A body area network (BAN) is a network of bodyworn or implanted electronic devices, including wireless sensors which can monitor body parameters or to detect movements. One of the big challenges in BANs is the propagation channel modeling. Channel models can be used to understand wave propagation in
Radio channel modeling in body area networks
An, L.; Bentum, M.J.; Meijerink, A.; Scanlon, W.G.
2009-01-01
A body area network (BAN) is a network of bodyworn or implanted electronic devices, including wireless sensors which can monitor body parameters or to de- tect movements. One of the big challenges in BANs is the propagation channel modeling. Channel models can be used to understand wave propagation
Critical stability of few-body systems
Karmanov, V A
2013-01-01
When a two-body system is bound by a zero-range interaction, the corresponding three-body system -- considered in a non-relativistic framework -- collapses, that is its binding energy is unbounded from below. In a paper by J.V. Lindesay and H.P. Noyes it was shown that the relativistic effects result in an effective repulsion in such a way that three-body binding energy remains also finite, thus preventing the three-body system from collapse. Later, this property was confirmed in other works based on different versions of relativistic approaches. However, the three-body system exists only for a limited range of two-body binding energy values. For stronger two-body interaction, the relativistic three-body system still collapses. A similar phenomenon was found in a two-body systems themselves: a two-fermion system with one-boson exchange interaction in a state with zero angular momentum J=0 exists if the coupling constant does not exceed some critical value but it also collapses for larger coupling constant. Fo...
Energy Technology Data Exchange (ETDEWEB)
Han, Kyungreem [College of Pharmacy and Research Institute of Pharmaceutical Sciences, Seoul National University, Seoul 151-742 (Korea, Republic of); Kang, Hyuk [National Institute for Mathematical Sciences, Daejeon 305-340 (Korea, Republic of); Choi, M.Y., E-mail: mychoi@snu.ac.kr [Department of Physics and Astronomy and Center for Theoretical Physics, Seoul National University, Seoul 151-747 (Korea, Republic of); Kim, Jinwoong, E-mail: jwkim@snu.ac.kr [College of Pharmacy and Research Institute of Pharmaceutical Sciences, Seoul National University, Seoul 151-742 (Korea, Republic of); Lee, Myung-Shik [Department of Medicine, Samsung Medical Center, and School of Medicine, Sungkyunkwan University, Seoul 135-710 (Korea, Republic of)
2012-10-01
A theoretical approach to the glucose–insulin regulatory system is presented. By means of integrated mathematical modeling and extensive numerical simulations, we probe the cell-level dynamics of the membrane potential, intracellular Ca{sup 2+} concentration, and insulin secretion in pancreatic β-cells, together with the whole-body level glucose–insulin dynamics in the liver, brain, muscle, and adipose tissues. In particular, the three oscillatory modes of insulin secretion are reproduced successfully. Such comprehensive mathematical modeling may provide a theoretical basis for the simultaneous assessment of the β-cell function and insulin resistance in clinical examination. -- Highlights: ► We present a mathematical model for the glucose–insulin regulatory system. ► This model combines the microscopic insulin secretion mechanism in a pancreatic β-cell and macroscopic glucose dynamics at the whole-body level. ► This work is expected to provide a theoretical basis for the simultaneous assessment of the β-cell function and insulin resistance in clinical examination.
Dance recognition system using lower body movement.
Simpson, Travis T; Wiesner, Susan L; Bennett, Bradford C
2014-02-01
The current means of locating specific movements in film necessitate hours of viewing, making the task of conducting research into movement characteristics and patterns tedious and difficult. This is particularly problematic for the research and analysis of complex movement systems such as sports and dance. While some systems have been developed to manually annotate film, to date no automated way of identifying complex, full body movement exists. With pattern recognition technology and knowledge of joint locations, automatically describing filmed movement using computer software is possible. This study used various forms of lower body kinematic analysis to identify codified dance movements. We created an algorithm that compares an unknown move with a specified start and stop against known dance moves. Our recognition method consists of classification and template correlation using a database of model moves. This system was optimized to include nearly 90 dance and Tai Chi Chuan movements, producing accurate name identification in over 97% of trials. In addition, the program had the capability to provide a kinematic description of either matched or unmatched moves obtained from classification recognition.
Made-to-measure N-body systems
Syer, D
1996-01-01
We describe an algorithm for constructing N-body realisations of equilibrium stellar systems. The algorithm complements existing orbit-based modelling techniques using linear programming or other optimization algorithms. The equilibria are constructed by integrating an N-body system while slowly adjusting the masses of the particles until the time-averaged density field and other observables converge to a prescribed value. The procedure can be arranged to maximise a linear combination of the entropy of the system and the \\chi^2 statistic for the observables. The equilibria so produced may be useful as initial conditions for N-body simulations or for modelling observations of individual galaxies.
[BODIES ARTIFACTS AND ANATOMICAL MODELS].
Aruta, Alessandro
2015-01-01
Through three different museological approaches, diachronically arranged, the essay intends to introduce some pertinent questions related to the topic of the conference "Bodies and Anatomy: the corpses in the museums from Ruysch to Von Hagens. The first item analyzes a recent line of British museological studies, treating mainly medical British museums of the XVIII and XIX century, with intriguing developments arriving up to nowadays. A second point illustrates several aspects with regards to the donation and the arrangement of the morbid specimina Luigi Gedda collection, coming from the CSS Mendel of Rome to the Museum of Pathological Anatomy of Sapienza University of Rome. Finally, in a crossover between the previous points, it will be presented some recent studies regarding the employment of new communication technologies in the scientific and medical museology.
0{sup +} ground state dominance in many-body systems
Energy Technology Data Exchange (ETDEWEB)
Zhao, Yu-Min [Southeast Univ., Dept. of Physics, Nanjing (China); Arima, Akito [The House of Councilors, Tokyo (Japan); Yoshinaga, Naotaka [Saitama Univ., Physics Dept., Saitama (Japan)
2002-12-01
We propose a simple approach to predict the angular momentum I ground states (Ig.s.) probabilities of many-body systems without diagonalization of the hamiltonian using random interactions. It is suggested that the 0g.s. dominance in boson systems and even valence nucleon systems is not given by the model space as previously assumed, but by specific two-body interactions. (author)
Human body modeling in injury biomechanics
Happee, R.; Morsink, P.L.J.; Horst, M.J. van der; Wismans, J.S.H.M.
1999-01-01
Mathematical modelling is widely used for crash-safety research and design. However, most occupant models used in crash simulations are based on crash dummies and thereby inherit their apparent limitations. This paper describes a mathematical model of the real human body for impact loading. A combin
A review of radio channel models for body centric communications
Cotton, Simon L.; D'Errico, Raffaele; Oestges, Claude
2014-06-01
The human body is an extremely challenging environment for the operation of wireless communications systems, not least because of the complex antenna-body electromagnetic interaction effects which can occur. This is further compounded by the impact of movement and the propagation characteristics of the local environment which all have an effect upon body centric communications channels. As the successful design of body area networks (BANs) and other types of body centric system is inextricably linked to a thorough understanding of these factors, the aim of this paper is to conduct a survey of the current state of the art in relation to propagation and channel models primarily for BANs but also considering other types of body centric communications. We initially discuss some of the standardization efforts performed by the Institute of Electrical and Electronics Engineers 802.15.6 task group before focusing on the two most popular types of technologies currently being considered for BANs, namely narrowband and Ultrawideband (UWB) communications. For narrowband communications the applicability of a generic path loss model is contended, before presenting some of the scenario specific models which have proven successful. The impacts of human body shadowing and small-scale fading are also presented alongside some of the most recent research into the Doppler and time dependencies of BANs. For UWB BAN communications, we again consider the path loss as well as empirical tap delay line models developed from a number of extensive channel measurement campaigns conducted by research institutions around the world. Ongoing efforts within collaborative projects such as Committee on Science and Technology Action IC1004 are also described. Finally, recent years have also seen significant developments in other areas of body centric communications such as off-body and body-to-body communications. We highlight some of the newest relevant research in these areas as well as discussing
A review of radio channel models for body centric communications.
Cotton, Simon L; D'Errico, Raffaele; Oestges, Claude
2014-06-01
The human body is an extremely challenging environment for the operation of wireless communications systems, not least because of the complex antenna-body electromagnetic interaction effects which can occur. This is further compounded by the impact of movement and the propagation characteristics of the local environment which all have an effect upon body centric communications channels. As the successful design of body area networks (BANs) and other types of body centric system is inextricably linked to a thorough understanding of these factors, the aim of this paper is to conduct a survey of the current state of the art in relation to propagation and channel models primarily for BANs but also considering other types of body centric communications. We initially discuss some of the standardization efforts performed by the Institute of Electrical and Electronics Engineers 802.15.6 task group before focusing on the two most popular types of technologies currently being considered for BANs, namely narrowband and Ultrawideband (UWB) communications. For narrowband communications the applicability of a generic path loss model is contended, before presenting some of the scenario specific models which have proven successful. The impacts of human body shadowing and small-scale fading are also presented alongside some of the most recent research into the Doppler and time dependencies of BANs. For UWB BAN communications, we again consider the path loss as well as empirical tap delay line models developed from a number of extensive channel measurement campaigns conducted by research institutions around the world. Ongoing efforts within collaborative projects such as Committee on Science and Technology Action IC1004 are also described. Finally, recent years have also seen significant developments in other areas of body centric communications such as off-body and body-to-body communications. We highlight some of the newest relevant research in these areas as well as discussing
A generic detailed rigid-body lumbar spine model
DEFF Research Database (Denmark)
De Zee, Mark; Hansen, Lone; Wong, Christian
2007-01-01
effort of different research groups. The model is defined in a text-based, declarative, object-oriented language in the AnyBody Modelling System software. Text-based models will facilitate sharing of the models between different research groups. The necessary data for the model has been taken from...... is relatively easy to share and modify due to the use of a well-defined and self-contained scripting language. Validation is though still necessary for specific cases....
Chaotic dynamics in N-body systems
Boekholt, Tjarda Coenraad Nico
2015-01-01
Ever since Isaac Newton in 1687 posed the N-body problem, astronomers have been looking for its solutions in order to understand the evolution of dynamical systems, such as our own solar system, star clusters and galaxies. The main difficulty is that small errors grow exponentially, so that numerica
Dynamic Human Body Modeling Using a Single RGB Camera.
Zhu, Haiyu; Yu, Yao; Zhou, Yu; Du, Sidan
2016-03-18
In this paper, we present a novel automatic pipeline to build personalized parametric models of dynamic people using a single RGB camera. Compared to previous approaches that use monocular RGB images, our system can model a 3D human body automatically and incrementally, taking advantage of human motion. Based on coarse 2D and 3D poses estimated from image sequences, we first perform a kinematic classification of human body parts to refine the poses and obtain reconstructed body parts. Next, a personalized parametric human model is generated by driving a general template to fit the body parts and calculating the non-rigid deformation. Experimental results show that our shape estimation method achieves comparable accuracy with reconstructed models using depth cameras, yet requires neither user interaction nor any dedicated devices, leading to the feasibility of using this method on widely available smart phones.
1974-06-01
might be to sum the signals directly using complex algebra . This approach may better be handled in a digital system. Servovalve Magnetic Coupling The...France, 1969. *’ 18. L- Coven and C. F. Durbin , A Cmprehensive Eigensolution Program for Structural Vibration Analysis TEV 142. Boeing Document D6
Electromagnetics of body area networks antennas, propagation, and RF systems
Werner, Douglas H
2016-01-01
The book is a comprehensive treatment of the field, covering fundamental theoretical principles and new technological advancements, state-of-the-art device design, and reviewing examples encompassing a wide range of related sub-areas. In particular, the first area focuses on the recent development of novel wearable and implantable antenna concepts and designs including metamaterial-based wearable antennas, microwave circuit integrated wearable filtering antennas, and textile and/or fabric material enabled wearable antennas. The second set of topics covers advanced wireless propagation and the associated statistical models for on-body, in-body, and off-body modes. Other sub-areas such as efficient numerical human body modeling techniques, artificial phantom synthesis and fabrication, as well as low-power RF integrated circuits and related sensor technology are also discussed. These topics have been carefully selected for their transformational impact on the next generation of body-area network systems and beyo...
Accurate upper body rehabilitation system using kinect.
Sinha, Sanjana; Bhowmick, Brojeshwar; Chakravarty, Kingshuk; Sinha, Aniruddha; Das, Abhijit
2016-08-01
The growing importance of Kinect as a tool for clinical assessment and rehabilitation is due to its portability, low cost and markerless system for human motion capture. However, the accuracy of Kinect in measuring three-dimensional body joint center locations often fails to meet clinical standards of accuracy when compared to marker-based motion capture systems such as Vicon. The length of the body segment connecting any two joints, measured as the distance between three-dimensional Kinect skeleton joint coordinates, has been observed to vary with time. The orientation of the line connecting adjoining Kinect skeletal coordinates has also been seen to differ from the actual orientation of the physical body segment. Hence we have proposed an optimization method that utilizes Kinect Depth and RGB information to search for the joint center location that satisfies constraints on body segment length and as well as orientation. An experimental study have been carried out on ten healthy participants performing upper body range of motion exercises. The results report 72% reduction in body segment length variance and 2° improvement in Range of Motion (ROM) angle hence enabling to more accurate measurements for upper limb exercises.
Level rearrangement in three-body systems
Richard, Jean-Marc
2016-01-01
We study systems of three bosons bound by a long-range interaction supplemented by a short-range potential of variable strength. This generalizes the usual two-body exotic atoms where the Coulomb interaction is modified by nuclear forces at short distances. The energy shift due to the short-range part of the interaction combines two-body terms similar to the ones entering the Trueman-Deser formula, and three-body contributions. A phenomenon of level rearrangement is observed, similar to the Zel'dovich effect, by the onset of an additional stable level which is eventually absorbed by the two-body threshold energy, and can be interpreted as an Efimov-like state of the short-range potential.
Visuals and Visualisation of Human Body Systems
Mathai, Sindhu; Ramadas, Jayashree
2009-01-01
This paper explores the role of diagrams and text in middle school students' understanding and visualisation of human body systems. We develop a common framework based on structure and function to assess students' responses across diagram and verbal modes. Visualisation is defined in terms of understanding transformations on structure and relating…
Examining a model of dispositional mindfulness, body comparison, and body satisfaction
Dijkstra, Pieternel; Barelds, Dick P. H.
2011-01-01
The present study examined the links between dispositional mindfulness, body comparison, and body satisfaction. It was expected that mindfulness would be associated with less body comparison and more body satisfaction. Two models were tested: one exploring body comparison as a mediator between mindf
Institute of Scientific and Technical Information of China (English)
陈景超; 阿里甫·库尔班
2012-01-01
Human Modelling is the premise of sign language synthesis system. Adopting VRML-based 3D body model can improve its performance, and can lay a good foundation for sign language synthesis system. In the design of 3D body model based on VRML, we analyse the theory of change control and the affine transformation approach of body model. By using wireframe model we realise 3D body modelling. By using affine transformation we realise arm controlled movement of body model. Experimental results show that this method is effective and feasible.%人体建模技术是实现手语合成系统的前提,采用VRML( Virtual Reality Modeling Language)三维人体建模技术可以提高人体建模的性能,为手语合成系统打下良好的基础.在基于VRML三维人体模型的设计中,分析了人体模型的控制变化原理及仿射变换方法；采用线框模型实现了三维人体模型的建立,运用仿射变换方法实现人体模型的手臂控制运动.实验结果证明该方法可行有效.
Models and microbiology: Pasteur and the body.
Hanley, James G
2003-01-01
Louis Pasteur developed a model of the body as a culture vessel in the late 1870s as an explanation of both natural and acquired immunity, and other investigators quickly applied the model in the explanation of other microbiological phenomena, principally the tissue tropism seen in the normal and the pathological flora. This paper will argue that although Pasteur quickly abandoned the model, it persisted as an explanation of tissue tropism for nearly 70 years, structuring the interpretation of data by and guiding the research of a diverse group of microbiological researchers.
Rigid multibody system dynamics with uncertain rigid bodies
Energy Technology Data Exchange (ETDEWEB)
Batou, A., E-mail: anas.batou@univ-paris-est.fr; Soize, C., E-mail: christian.soize@univ-paris-est.fr [Universite Paris-Est, Laboratoire Modelisation et Simulation Multi Echelle, MSME UMR 8208 CNRS (France)
2012-03-15
This paper is devoted to the construction of a probabilistic model of uncertain rigid bodies for multibody system dynamics. We first construct a stochastic model of an uncertain rigid body by replacing the mass, the center of mass, and the tensor of inertia by random variables. The prior probability distributions of the stochastic model are constructed using the maximum entropy principle under the constraints defined by the available information. The generators of independent realizations corresponding to the prior probability distribution of these random quantities are further developed. Then several uncertain rigid bodies can be linked to each other in order to calculate the random response of a multibody dynamical system. An application is proposed to illustrate the theoretical development.
Quantum scaling in many-body systems
Continentino, Mucio A
2001-01-01
This book on quantum phase transitions has been written by one of the pioneers in the application of scaling ideas to many-body systems - a new and exciting subject that has relevance to many areas of condensed matter and theoretical physics. One of the few books on the subject, it emphasizes strongly correlated electronic systems. Although dealing with complex problems in statistical mechanics, it does not lose sight of the experiments and the actual physical systems which motivate the theoretical work. The book starts by presenting the scaling theory of quantum critical phenomena. Critical e
Solar Electric Bicycle Body Modeling and Simulation
Directory of Open Access Journals (Sweden)
Zhikun Wang
2013-10-01
Full Text Available A new solar electric bicycle design and study were carried out on in this paper. Application of CAD technology to establish three-dimension geometric model, using the kinetic analysis on the frame and other parts for numerical simulation and static strength analysis for the vehicle model design, virtual assembly, complete frame dynamics analysis and vibration analysis, with considering other factors, first on the frame structure improvement, second on security of design calculation analysis and comparison, finally get the ideal body design.
Whole body acid-base modeling revisited.
Ring, Troels; Nielsen, Søren
2017-04-01
The textbook account of whole body acid-base balance in terms of endogenous acid production, renal net acid excretion, and gastrointestinal alkali absorption, which is the only comprehensive model around, has never been applied in clinical practice or been formally validated. To improve understanding of acid-base modeling, we managed to write up this conventional model as an expression solely on urine chemistry. Renal net acid excretion and endogenous acid production were already formulated in terms of urine chemistry, and we could from the literature also see gastrointestinal alkali absorption in terms of urine excretions. With a few assumptions it was possible to see that this expression of net acid balance was arithmetically identical to minus urine charge, whereby under the development of acidosis, urine was predicted to acquire a net negative charge. The literature already mentions unexplained negative urine charges so we scrutinized a series of seminal papers and confirmed empirically the theoretical prediction that observed urine charge did acquire negative charge as acidosis developed. Hence, we can conclude that the conventional model is problematic since it predicts what is physiologically impossible. Therefore, we need a new model for whole body acid-base balance, which does not have impossible implications. Furthermore, new experimental studies are needed to account for charge imbalance in urine under development of acidosis.
Carey, Renee N; Donaghue, Ngaire; Broderick, Pia
2014-01-01
This study investigated the potential mediating roles of body comparisons with peers and models in the relationship between the internalization of thinness norms and body image concern. A total of 224 Western Australian girls aged 14-15 completed questionnaires assessing their endorsement of thinness norms, body image concerns, and frequency of body comparisons with peers and with models. Both targets of body comparisons were found to significantly mediate the relationship between the endorsement of thinness norms and body image concern, with body comparison with peers a stronger mediator than comparison with models. These findings show that body comparison with peers, in particular, plays a significant role in the experience of body image concerns among adolescent girls, and should be given a higher profile in programs designed to prevent or reduce body image concern.
Three-Body Potentials in {\\varvec{α }}-Particle Model of Light Nuclei
Ishikawa, Souichi
2017-03-01
In three-body model calculations of atomic nuclei, e.g., the {}^{12}C nucleus as α -α -α system and the {}9Be nucleus as α -α - n system, the Hamiltonians of the systems consisting of two- and three-body potentials are important inputs. However, our knowledge of three-body potentials is quite restricted. In this paper, I will examine a relation between α -α -α and α -α - n three-body potentials that is obtained in a simple cluster model picture, which gives a phenomenological constraint condition on the three-body potential models to be used.
Modelling body weight, dieting and obesity traps
Barbieri, Paolo Nicola
2017-02-01
This paper presents a theoretical investigation into why losing weight is so difficult even in the absence of rational addiction, time-inconsistent preferences or bounded rationality. We add to the existing literature by focusing on the role that individual metabolism has on weight loss. The results from the theoretical model provide multiple steady states and a threshold revealing a situation of "obesity traps" that the individual must surpass in order to successfully lose weight. Any weight-loss efforts that the individual undertakes have to surpass such threshold in order to result in permanent weight loss, otherwise the individual will gradually regain weight and converge to his or her previous body weight.
Body charge modelling for accurate simulation of small-signal behaviour in floating body SOI
Benson, James; Redman-White, William; D'Halleweyn, Nele V.; Easson, Craig A.; Uren, Michael J.
2002-04-01
We show that careful modelling of body node elements in floating body PD-SOI MOSFET compact models is required in order to obtain accurate small-signal simulation results in the saturation region. The body network modifies the saturation output conductance of the device via the body-source transconductance, resulting in a pole/zero pair being introduced in the conductance-frequency response. We show that neglecting the presence of body charge in the saturation region can often yield inaccurate values for the body capacitances, which in turn can adversely affect the modelling of the output conductance above the pole/zero frequency. We conclude that the underlying cause of this problem is the use of separate models for the intrinsic and extrinsic capacitances. Finally, we present a simple saturation body charge model which can greatly improve small-signal simulation accuracy for floating body devices.
On the dynamics of a human body model.
Huston, R. L.; Passerello, C. E.
1971-01-01
Equations of motion for a model of the human body are developed. Basically, the model consists of an elliptical cylinder representing the torso, together with a system of frustrums of elliptical cones representing the limbs. They are connected to the main body and each other by hinges and ball and socket joints. Vector, tensor, and matrix methods provide a systematic organization of the geometry. The equations of motion are developed from the principles of classical mechanics. The solution of these equations then provide the displacement and rotation of the main body when the external forces and relative limb motions are specified. Three simple example motions are studied to illustrate the method. The first is an analysis and comparison of simple lifting on the earth and the moon. The second is an elementary approach to underwater swimming, including both viscous and inertia effects. The third is an analysis of kicking motion and its effect upon a vertically suspended man such as a parachutist.
Impact injury prediction by FE human body model
Directory of Open Access Journals (Sweden)
Hynčík L.
2008-12-01
Full Text Available The biomechanical simulations as powerful instruments are used in many areas such as traffic, medicine, sport, army etc. The simulations are often performed with models, which are based on the Finite Element Method. The great ability of FE deformable models of human bodies is to predict the injuries during accidents. Due to its modular implementation of thorax and abdomen FE models, human articulated rigid body model ROBBY, which was previously developed at the University of West Bohemia in cooperation with ESI Group (Engineering Simulation for Industry, can be used for this purpose. ROBBY model representing average adult man is still being improved to obtain more precise model of human body with the possibility to predict injuries during accidents. Recently, new generated thoracic model was embedded into ROBBY model and this was subsequently satisfactorily validated. In this study the updated ROBBY model was used and injury of head and thorax were investigated during frontal crashes simulated by virtue of two types of sled tests with various types of restraint system (shoulder belt, lap belt and airbag. The results of the simulation were compared with the experimental ones.
Chemical evolution of primitive solar system bodies
Oro, J.; Mills, T.
1989-01-01
Observations on organic molecules and compounds containing biogenic elements in the interstellar medium and in the primitive bodies of the solar system are reviewed. The discovery of phosphorus molecular species in dense interstellar clouds, the existence of organic ions in the dust and gas phase of the comas of Comet Halley, and the presence of presolar, deuterium-hydrogen ratios in the amino acids of carbonaceous chondrites are discussed. The relationships between comets, dark asteroids, and carbonaceous chondrites are examined. Also, consideration is given to the chemical evolution of Titan, the primitive earth, and early Mars.
Tylka, Tracy L
2011-06-01
Although muscularity and body fat concerns are central to conceptualizing men's body image, they have not been examined together within existing structural models. This study refined the tripartite influence model (Thompson, Heinberg, Altabe, & Tantleff-Dunn, 1999) by including dual body image pathways (muscularity and body fat dissatisfaction) to engagement in muscular enhancement and disordered eating behaviors, respectively, and added dating partners as a source of social influence. Latent variable structural equation modeling analyses supported this quadripartite model in 473 undergraduate men. Nonsignificant paths were trimmed and two unanticipated paths were added. Muscularity dissatisfaction and body fat dissatisfaction represented dual body image pathways to men's engagement in muscularity enhancement behaviors and disordered eating behaviors, respectively. Pressures to be mesomorphic from friends, family, media, and dating partners made unique contributions to the model. Internalization of the mesomorphic ideal, muscularity dissatisfaction, and body fat dissatisfaction played key meditational roles within the model.
A modular approach to numerical human body modeling
Forbes, P.A.; Griotto, G.; Rooij, L. van
2007-01-01
The choice of a human body model for a simulated automotive impact scenario must take into account both accurate model response and computational efficiency as key factors. This study presents a "modular numerical human body modeling" approach which allows the creation of a customized human body mod
Periodically driven ergodic and many-body localized quantum systems
Energy Technology Data Exchange (ETDEWEB)
Ponte, Pedro [Perimeter Institute for Theoretical Physics, Waterloo, ON N2L 2Y5 (Canada); Department of Physics and Astronomy, University of Waterloo, ON N2L 3G1 (Canada); Chandran, Anushya [Perimeter Institute for Theoretical Physics, Waterloo, ON N2L 2Y5 (Canada); Papić, Z., E-mail: zpapic@perimeterinstitute.ca [Perimeter Institute for Theoretical Physics, Waterloo, ON N2L 2Y5 (Canada); Institute for Quantum Computing, Waterloo, ON N2L 3G1 (Canada); Abanin, Dmitry A. [Perimeter Institute for Theoretical Physics, Waterloo, ON N2L 2Y5 (Canada); Institute for Quantum Computing, Waterloo, ON N2L 3G1 (Canada)
2015-02-15
We study dynamics of isolated quantum many-body systems whose Hamiltonian is switched between two different operators periodically in time. The eigenvalue problem of the associated Floquet operator maps onto an effective hopping problem. Using the effective model, we establish conditions on the spectral properties of the two Hamiltonians for the system to localize in energy space. We find that ergodic systems always delocalize in energy space and heat up to infinite temperature, for both local and global driving. In contrast, many-body localized systems with quenched disorder remain localized at finite energy. We support our conclusions by numerical simulations of disordered spin chains. We argue that our results hold for general driving protocols, and discuss their experimental implications.
Réal, Florent; Vallet, Valérie; Flament, Jean-Pierre; Masella, Michel
2013-09-21
We present a revised version of the water many-body model TCPE [M. Masella and J.-P. Flament, J. Chem. Phys. 107, 9105 (1997)], which is based on a static three charge sites and a single polarizable site to model the molecular electrostatic properties of water, and on an anisotropic short range many-body energy term specially designed to accurately model hydrogen bonding in water. The parameters of the revised model, denoted TCPE/2013, are here developed to reproduce the ab initio energetic and geometrical properties of small water clusters (up to hexamers) and the repulsive water interactions occurring in cation first hydration shells. The model parameters have also been refined to reproduce two liquid water properties at ambient conditions, the density and the vaporization enthalpy. Thanks to its computational efficiency, the new model range of applicability was validated by performing simulations of liquid water over a wide range of temperatures and pressures, as well as by investigating water liquid/vapor interfaces over a large range of temperatures. It is shown to reproduce several important water properties at an accurate enough level of precision, such as the existence liquid water density maxima up to a pressure of 1000 atm, the water boiling temperature, the properties of the water critical point (temperature, pressure, and density), and the existence of a "singularity" temperature at about 225 K in the supercooled regime. This model appears thus to be particularly well-suited for characterizing ion hydration properties under different temperature and pressure conditions, as well as in different phases and interfaces.
Integrable systems, toric degenerations and Okounkov bodies
Harada, Megumi
2012-01-01
Let X be a smooth projective variety of dimension n over C equipped with a very ample line bundle L. Using the theory of Okounkov bodies and an associated toric degeneration, we construct -- under a mild technical hypothesis on X -- an integrable system on X in the sense of symplectic geometry. More precisely, we construct a collection of real-valued functions {H_1, ..., H_n} on X which are continuous on all of X, smooth on an open dense subset U of X, and pairwise Poisson-commute on U. Here the symplectic structure on X is the pullback of the Fubini-Study form on P(H^0(X, L)^*) via the Kodaira embedding. The image of the `moment map' (H_1, ..., H_n): X to R^n is precisely the Okounkov body \\Delta = \\Delta(R, v) associated to the homogeneous coordinate ring R of X, and an appropriate choice of valuation v on R. Our main technical tools come from algebraic geometry, differential (Kaehler) geometry, and analysis. Specifically, we use: a toric degeneration of X to a (not necessarily normal) toric variety X_0, th...
Nonlinear dynamics mathematical models for rigid bodies with a liquid
Lukovsky, Ivan A
2015-01-01
This book is devoted to analytically approximate methods in the nonlinear dynamics of a rigid body with cavities partly filled by liquid. It combines several methods and compares the results with experimental data. It is useful for experienced and early-stage readers interested in analytical approaches to fluid-structure interaction problems, the fundamental mathematical background and modeling the dynamics of such complex mechanical systems.
Springgay, Stephanie
2009-01-01
Arguing for new models of inquiry that interrogate body image from the perspective of intercorporeality, this article explores a research study conducted in a secondary school art class. Shifting analysis from the representation of body image to a tactile, sensuous, and experiential understanding of body image, I highlight the contradictions and…
Irreducible many-body correlations in topologically ordered systems
Liu, Yang; Zeng, Bei; Zhou, D. L.
2016-02-01
Topologically ordered systems exhibit large-scale correlation in their ground states, which may be characterized by quantities such as topological entanglement entropy. We propose that the concept of irreducible many-body correlation (IMC), the correlation that cannot be implied by all local correlations, may also be used as a signature of topological order. In a topologically ordered system, we demonstrate that for a part of the system with holes, the reduced density matrix exhibits IMCs which become reducible when the holes are removed. The appearance of these IMCs then represents a key feature of topological phase. We analyze the many-body correlation structures in the ground state of the toric code model in external magnetic fields, and show that the topological phase transition is signaled by the IMCs.
Study on movement inertia in the Earth multi-body system
Institute of Scientific and Technical Information of China (English)
CHEN; Xiaofei; BI; Siwen; GONG; Huili
2006-01-01
This paper summarizes the first movement and mass centre of stratum-block movement inertia in the Earth multi-body system and introduces its application. It also elaborates the moment of inertia and the products of inertia: the inertia dyadic transformation of reference system and the parallel axis theorem of stratum-block movement inertia of the Earth multi-body system. It provides an academic foundation for research on the dynamic model of Earth multi-body system.
The Body Center Cubic Quark Lattice Model
Lin Xu, Jiao
2004-01-01
The Standard Model while successful in many ways is incomplete; many questions remain. The origin of quark masses and hadronization of quarks are awaiting an answer. From the Dirac sea concept, we infer that two kinds of elementary quarks (u(0) and d(0)) constitute a body center cubic (BCC) quark lattice with a lattice constant a < $10^{-18}$m in the vacuum. Using energy band theory and the BCC quark lattice, we can deduce the rest masses and the intrinsic quantum numbers (I, S, C, b and Q) of quarks. With the quark spectrum, we deduce a baryon spectrum. The theoretical spectrum is in agreement well with the experimental results. Not only will this paper provide a physical basis for the Quark Model, but also it will open a door to study the more fundamental nature at distance scales <$10^{-18}$m. This paper predicts some new quarks $u_{c}$(6490) and d$_{b}$(9950), and new baryons $\\Lambda_{c}^{+}$(6500), $\\Lambda_{b}^{0}$(9960).
A topological multilayer model of the human body.
Barbeito, Antonio; Painho, Marco; Cabral, Pedro; O'Neill, João
2015-11-04
Geographical information systems deal with spatial databases in which topological models are described with alphanumeric information. Its graphical interfaces implement the multilayer concept and provide powerful interaction tools. In this study, we apply these concepts to the human body creating a representation that would allow an interactive, precise, and detailed anatomical study. A vector surface component of the human body is built using a three-dimensional (3-D) reconstruction methodology. This multilayer concept is implemented by associating raster components with the corresponding vector surfaces, which include neighbourhood topology enabling spatial analysis. A root mean square error of 0.18 mm validated the three-dimensional reconstruction technique of internal anatomical structures. The expansion of the identification and the development of a neighbourhood analysis function are the new tools provided in this model.
Many-Body Boson Systems Half a Century Later
Verbeure, André F
2011-01-01
Many-body Boson Systems: Half a Century Later offers a modern way of dealing with the problems of equilibrium states of Bose systems. Starting with the variation principle of statistical mechanics and the energy-entropy balance principle as equilibrium criteria, results for general boson systems and models are explicitly derived using simple functional analytic calculus. Bridging the gap between idea’s of general theoretical physics and the phenomenological research in the field of Bose systems, this book provides an insight into the fascinating quantum world of bosons. Key topics include the occurrence of BEC and its intimate structural relation with the phenomena of spontaneous symmetry breaking and off-diagonal long range order; the condensate equation; the issue concerning the choice of boundary conditions; solvable versus non-solvable boson models; the set of quasi-free boson states; the role of dissipative perturbations; and the surprising but general relation between general quantum fluctuations and ...
Classical and quantum simulations of many-body systems
Energy Technology Data Exchange (ETDEWEB)
Murg, Valentin
2008-04-07
This thesis is devoted to recent developments in the fields of classical and quantum simulations of many-body systems. We describe new classical algorithms that overcome problems apparent in conventional renormalization group and Monte Carlo methods. These algorithms make possible the detailed study of finite temperature properties of 2-D classical and 1-D quantum systems, the investigation of ground states of 2-D frustrated or fermionic systems and the analysis of time evolutions of 2-D quantum systems. Furthermore, we propose new 'analog' quantum simulators that are able to realize interesting models such as a Tonks-Girardeau gas or a frustrated spin-1/2 XY model on a trigonal lattice. These quantum simulators make use of optical lattices and trapped ions and are technically feasible. In fact, the Tonks-Girardeau gas has been realized experimentally and we provide a detailed comparison between the experimental data and the theoretical predictions. (orig.)
Modeling Rotating Turbulent Flows with the Body Force Potential Model.
Bhattacharya, Amitabh; Perot, Blair
2000-11-01
Like a Reynolds Stress Transport equation model, the turbulent potential model has an explicit Coriolis acceleration term that appears in the model that accounts for rotation effects. In this work the additional secondary effects that system rotation has on the dissipation rate, return-to-isotropy, and fast pressure strain terms are also included in the model. The resulting model is tested in the context of rotating isotropic turbulence, rotating homogeneous shear flow, rotating channel flow, and swirling pipe flow. Many of the model changes are applicable to Reynolds stress transport equation models. All model modifications are frame indifferent.
Exactly solvable models in many-body theory
March, N H
2016-01-01
The book reviews several theoretical, mostly exactly solvable, models for selected systems in condensed states of matter, including the solid, liquid, and disordered states, and for systems of few or many bodies, both with boson, fermion, or anyon statistics. Some attention is devoted to models for quantum liquids, including superconductors and superfluids. Open problems in relativistic fields and quantum gravity are also briefly reviewed.The book ranges almost comprehensively, but concisely, across several fields of theoretical physics of matter at various degrees of correlation and at different energy scales, with relevance to molecular, solid-state, and liquid-state physics, as well as to phase transitions, particularly for quantum liquids. Mostly exactly solvable models are presented, with attention also to their numerical approximation and, of course, to their relevance for experiments.
A new model for programming software in body sensor networks.
de A Barbosa, Talles M G; Sene, Iwens G; da Rocha, Adson F; de O Nascimento, Francisco A A; Carvalho, Joao L A; Carvalho, Hervaldo S
2007-01-01
A Body Sensor Network (BSN) must be designed to work autonomously. On the other hand, BSNs need mechanisms that allow changes in their behavior in order to become a clinically useful tool. The purpose of this paper is to present a new programming model that will be useful for programming BSN sensor nodes. This model is based on an intelligent intermediate-level compiler. The main purpose of the proposed compiler is to increase the efficiency in system use, and to increase the lifetime of the application, considering its requirements, hardware possibilities and specialist knowledge. With this model, it is possible to maintain the autonomous operation capability of the BSN and still offer tools that allow users with little grasp on programming techniques to program these systems.
Long, W. S.
1977-01-01
Attempts are made to generate acceptable coordinate systems for two-body configurations. The first method to be tried was to use the body-fitted coordinate system technique to obtain the best system. This technique alone did not produce very good results, so another approach was investigated. This new approach involved using a combination of the body fitted coordinate system procedure and a complex variable transformation method that was used successfully in conformal mapping.
Discrimination of Body Odor Using Odor Sieving Sensor System
Takamizawa, Tadashi; Miyagi, Kazuki; Miyauchi, Hitoshi; Imahashi, Masahiro; Hayashi, Kenshi
2011-09-01
We have been focusing on sebum for discriminating human body odor. In this study, we examined body odor sampled from 12 male examinees. Through the experiment, we detected statistically-significant differences between 56 pairs of examinees out of 66 pairs (approximately 85%). This result shows that our system and principle enabled discrimination of body odor between examinees to a certain extent.
Predicting body appreciation in young women: An integrated model of positive body image.
Andrew, Rachel; Tiggemann, Marika; Clark, Levina
2016-09-01
This study examined a range of predictors, based on previous theoretical models, of positive body image in young adult women. Participants were 266 women who completed an online questionnaire measuring body appreciation, activity participation, media consumption, perceived body acceptance by others, self-compassion, and autonomy. Potential mechanisms in predicting body appreciation assessed were self-objectification, social appearance comparison, and thin-ideal internalisation. Results indicated that greater perceived body acceptance by others and self-compassion, and lower appearance media consumption, self-objectification, social comparison, and thin-ideal internalisation were related to greater body appreciation. An integrated model showed that appearance media (negatively) and non-appearance media and self-compassion (positively) were associated with lower self-objectification, social comparison, and thin-ideal internalisation, which in turn related to greater body appreciation. Additionally, perceived body acceptance by others was directly associated with body appreciation. The results contribute to an understanding of potential pathways of positive body image development, thereby highlighting possible intervention targets.
Health Monitoring System Based on Intra-Body Communication
Razak, A. H. A.; Ibrahim, I. W.; Ayub, A. H.; Amri, M. F.; Hamzi, M. H.; Halim, A. K.; Ahmad, A.; Junid, S. A. M. Al
2015-11-01
This paper presents a model of a Body Area Network (BAN) health monitoring system based on Intra-Body Communication. Intra-body Communication (IBC) is a communication technique that uses the human body as a medium for electrical signal communication. One of the visions in the health care industry is to provide autonomous and continuous self and the remote health monitoring system. This can be achieved via BAN, LAN and WAN integration. The BAN technology itself consists of short range data communication modules, sensors, controller and actuators. The information can be transmitted to the LAN and WAN via the RF technology such as Bluetooth, ZigBee and ANT. Although the implementations of RF communication have been successful, there are still limitations in term of power consumption, battery lifetime, interferences and signal attenuations. One of the solutions for Medical Body Area Network (MBANs) to overcome these issues is by using an IBC technique because it can operate at lower frequencies and power consumption compared to the existing techniques. The first objective is to design the IBC's transmitter and receiver modules using the off the shelf components. The specifications of the modules such as frequency, data rate, modulation and demodulation coding system were defined. The individual module were designed and tested separately. The modules was integrated as an IBC system and tested for functionality then was implemented on PCB. Next objective is to model and implement the digital parts of the transmitter and receiver modules on the Altera's FPGA board. The digital blocks were interfaced with the FPGA's on board modules and the discrete components. The signals that have been received from the transmitter were converted into a proper waveform and it can be viewed via external devices such as oscilloscope and Labview. The signals such as heartbeats or pulses can also be displayed on LCD. In conclusion, the IBC project presents medical health monitoring model
Analysis of an idealized body-vortex systems
DEFF Research Database (Denmark)
Pedersen, Johan Rønby; Aref, Hassan
2008-01-01
We explore the class of dynamical systems consisting of a body, N point vortices, and one or more passive particles in an ideal, unbounded, planar fluid. The body is represented by a closed curve and is free to move in response to the fluid motion. The vortices have fixed strengths and are intended...... in hand. They can be analyzed using techniques from the theory of dynamical systems with a finite number of degrees of freedom. The simplest such system, a single point vortex and a circular body, is integrable. If we add vortices, or change other features of the system such as the body shape, the motion...
Measuring entanglement entropy in a quantum many-body system
Rispoli, Matthew; Preiss, Philipp; Tai, Eric; Lukin, Alex; Schittko, Robert; Kaufman, Adam; Ma, Ruichao; Islam, Rajibul; Greiner, Markus
2016-05-01
The presence of large-scale entanglement is a defining characteristic of exotic quantum phases of matter. It describes non-local correlations between quantum objects, and is at the heart of quantum information sciences. However, measuring entanglement remains a challenge. This is especially true in systems of interacting delocalized particles, for which a direct experimental measurement of spatial entanglement has been elusive. Here we measure entanglement in such a system of itinerant particles using quantum interference of many-body twins. We demonstrate a novel approach to the measurement of entanglement entropy of any bosonic system, using a quantum gas microscope with tailored potential landscapes. This protocol enables us to directly measure quantum purity, Rényi entanglement entropy, and mutual information. In general, these experiments exemplify a method enabling the measurement and characterization of quantum phase transitions and in particular would be apt for studying systems such as magnetic ordering within the quantum Ising model.
Fermi golden rule for $N$-body systems in a black-body radiation
Ostilli, Massimo
2016-01-01
We review the calculation of the Fermi golden rule for a system of $N$-body dipoles, magnetic or electric, weakly interacting with a black-body radiation. By using the magnetic or electric field-field correlation function evaluated in the 1960s for the black body radiation, we deduce a general formula for the transition rates and study its limiting, fully coherent or fully incoherent, regimes.
Directory of Open Access Journals (Sweden)
Thomas eEissing
2011-02-01
Full Text Available Today, in silico studies and trial simulations already complement experimental approaches in pharmaceutical R&D and have become indispensable tools for decision making and communication with regulatory agencies. While biology is multi-scale by nature, project work and software tools usually focus on isolated aspects of drug action, such as pharmacokinetics at the organism scale or pharmacodynamic interaction on the molecular level. We present a modeling and simulation software platform consisting of PK-Sim® and MoBi® capable of building and simulating models that integrate across biological scales. A prototypical multiscale model for the progression of a pancreatic tumor and its response to pharmacotherapy is constructed and virtual patients are treated with a prodrug activated by hepatic metabolization. Tumor growth is driven by signal transduction leading to cell cycle transition and proliferation. Free tumor concentrations of the active metabolite inhibit Raf kinase in the signaling cascade and thereby cell cycle progression. In a virtual clinical study, the individual therapeutic outcome of the chemotherapeutic intervention is simulated for a large population with heterogeneous genomic background. Thereby, the platform allows efficient model building and integration of biological knowledge and prior data from all biological scales. Experimental in vitro model systems can be linked with observations in animal experiments and clinical trials. The interplay between patients, diseases, and drugs and topics with high clinical relevance such as the role of pharmacogenomics, drug-drug or drug-metabolite interactions can be addressed using this mechanistic, insight driven multiscale modeling approach.
Eissing, Thomas; Kuepfer, Lars; Becker, Corina; Block, Michael; Coboeken, Katrin; Gaub, Thomas; Goerlitz, Linus; Jaeger, Juergen; Loosen, Roland; Ludewig, Bernd; Meyer, Michaela; Niederalt, Christoph; Sevestre, Michael; Siegmund, Hans-Ulrich; Solodenko, Juri; Thelen, Kirstin; Telle, Ulrich; Weiss, Wolfgang; Wendl, Thomas; Willmann, Stefan; Lippert, Joerg
2011-01-01
Today, in silico studies and trial simulations already complement experimental approaches in pharmaceutical R&D and have become indispensable tools for decision making and communication with regulatory agencies. While biology is multiscale by nature, project work, and software tools usually focus on isolated aspects of drug action, such as pharmacokinetics at the organism scale or pharmacodynamic interaction on the molecular level. We present a modeling and simulation software platform consisting of PK-Sim(®) and MoBi(®) capable of building and simulating models that integrate across biological scales. A prototypical multiscale model for the progression of a pancreatic tumor and its response to pharmacotherapy is constructed and virtual patients are treated with a prodrug activated by hepatic metabolization. Tumor growth is driven by signal transduction leading to cell cycle transition and proliferation. Free tumor concentrations of the active metabolite inhibit Raf kinase in the signaling cascade and thereby cell cycle progression. In a virtual clinical study, the individual therapeutic outcome of the chemotherapeutic intervention is simulated for a large population with heterogeneous genomic background. Thereby, the platform allows efficient model building and integration of biological knowledge and prior data from all biological scales. Experimental in vitro model systems can be linked with observations in animal experiments and clinical trials. The interplay between patients, diseases, and drugs and topics with high clinical relevance such as the role of pharmacogenomics, drug-drug, or drug-metabolite interactions can be addressed using this mechanistic, insight driven multiscale modeling approach.
Predicting chick body mass by artificial intelligence-based models
Directory of Open Access Journals (Sweden)
Patricia Ferreira Ponciano Ferraz
2014-07-01
Full Text Available The objective of this work was to develop, validate, and compare 190 artificial intelligence-based models for predicting the body mass of chicks from 2 to 21 days of age subjected to different duration and intensities of thermal challenge. The experiment was conducted inside four climate-controlled wind tunnels using 210 chicks. A database containing 840 datasets (from 2 to 21-day-old chicks - with the variables dry-bulb air temperature, duration of thermal stress (days, chick age (days, and the daily body mass of chicks - was used for network training, validation, and tests of models based on artificial neural networks (ANNs and neuro-fuzzy networks (NFNs. The ANNs were most accurate in predicting the body mass of chicks from 2 to 21 days of age after they were subjected to the input variables, and they showed an R² of 0.9993 and a standard error of 4.62 g. The ANNs enable the simulation of different scenarios, which can assist in managerial decision-making, and they can be embedded in the heating control systems.
Physiological models of body composition and human obesity
Shapses Sue A; Pierson Richard N; Heymsfield Steven B; Levitt David G; Kral John G
2007-01-01
Abstract Background The body mass index (BMI) is the standard parameter for predicting body fat fraction and for classifying degrees of obesity. Currently available regression equations between BMI and fat are based on 2 or 3 parameter empirical fits and have not been validated for highly obese subjects. We attempt to develop regression relations that are based on realistic models of body composition changes in obesity. These models, if valid, can then be extrapolated to the high fat fraction...
Visualizing Astrophysical N-body Systems
Dubinski, John
2008-01-01
I begin with a brief history of N-body simulation and visualization and then go on to describe various methods for creating images and animations of modern simulations in cosmology and galactic dynamics. These techniques are incorporated into a specialized particle visualization software library called MYRIAD that is designed to render images within large parallel N-body simulations as they run. I present several case studies that explore the application of these methods to animations of star clusters, interacting galaxies and cosmological structure formation.
Dynamical Configurations of Celestial Systems Comprised of Multiple Irregular Bodies
Jiang, Yu; Baoyin, Hexi; Li, Junfeng
2016-01-01
This manuscript considers the main features of the nonlinear dynamics of multiple irregular celestial body systems. The gravitational potential, static electric potential, and magnetic potential are considered. Based on the three established potentials, we show that three conservative values exist for this system, including a Jacobi integral. The equilibrium conditions for the system are derived and their stability analyzed. The equilibrium conditions of a celestial system comprised of n irregular bodies are reduced to 12n minus 9 equations. The dynamical results are applied to simulate the motion of multiple-asteroid systems. The simulation is useful for the study of the stability of multiple irregular celestial body systems and for the design of spacecraft orbits to triple asteroid systems discovered in the solar system. The dynamical configurations of the five triple-asteroid systems 45 Eugenia, 87 Sylvia, 93 Minerva, 216 Kleopatra, and 136617 1994CC, and the six-body system 134340 Pluto are calculated and...
Research on Dynamic Model of the Human Body
Institute of Scientific and Technical Information of China (English)
ZHANG Chun-lin; WANG Guang-quan; LU Dun-yong
2005-01-01
After summarizing the current situation of the research on human body modeling, a new dynamic model containing 5 equivalent masses has been proposed and the corresponding dynamic equations has been deduced too. By using this new model, more detailed information about the situation of the human body under impact and vibration can be obtained. The new model solves the problem that transmission functions of forces inside the human body can't be deduced by using 3-equivalent-mass model. It will find its usage in many applications.
On point vortex models of exotic bluff body wakes
Energy Technology Data Exchange (ETDEWEB)
Stremler, Mark A; Basu, Saikat, E-mail: stremler@vt.edu [Department of Engineering Science and Mechanics, Virginia Tech, Blacksburg, VA 24061 (United States)
2014-12-01
Exotic vortex wakes, in which three or more vortices are generated during each shedding cycle, are frequently found in the wake of an oscillating bluff body. Two common examples are P+S wakes (with 3 vortices) and 2P wakes (with 4 vortices). We consider mathematical models of these wakes consisting of N = 3 or 4 point vortices with constant strengths in an inviscid fluid that is otherwise at rest in a singly-periodic domain. By enforcing constraints on the vortex strengths and, in the case of N = 4, on the symmetry of the vortex locations, the mathematical models reduce to integrable Hamiltonian systems. We compare the point vortex trajectories with two exotic wake patterns reported in the literature. Results support the use of point vortex modeling to investigate vortex dynamics in exotic wakes and suggest the need for additional classification of experimental wake patterns. (paper)
Integrating cellular metabolism into a multiscale whole-body model.
Directory of Open Access Journals (Sweden)
Markus Krauss
Full Text Available Cellular metabolism continuously processes an enormous range of external compounds into endogenous metabolites and is as such a key element in human physiology. The multifaceted physiological role of the metabolic network fulfilling the catalytic conversions can only be fully understood from a whole-body perspective where the causal interplay of the metabolic states of individual cells, the surrounding tissue and the whole organism are simultaneously considered. We here present an approach relying on dynamic flux balance analysis that allows the integration of metabolic networks at the cellular scale into standardized physiologically-based pharmacokinetic models at the whole-body level. To evaluate our approach we integrated a genome-scale network reconstruction of a human hepatocyte into the liver tissue of a physiologically-based pharmacokinetic model of a human adult. The resulting multiscale model was used to investigate hyperuricemia therapy, ammonia detoxification and paracetamol-induced toxication at a systems level. The specific models simultaneously integrate multiple layers of biological organization and offer mechanistic insights into pathology and medication. The approach presented may in future support a mechanistic understanding in diagnostics and drug development.
Objective estimation of body condition score by modeling cow body shape from digital images.
Azzaro, G; Caccamo, M; Ferguson, J D; Battiato, S; Farinella, G M; Guarnera, G C; Puglisi, G; Petriglieri, R; Licitra, G
2011-04-01
Body condition score (BCS) is considered an important tool for management of dairy cattle. The feasibility of estimating the BCS from digital images has been demonstrated in recent work. Regression machines have been successfully employed for automatic BCS estimation, taking into account information of the overall shape or information extracted on anatomical points of the shape. Despite the progress in this research area, such studies have not addressed the problem of modeling the shape of cows to build a robust descriptor for automatic BCS estimation. Moreover, a benchmark data set of images meant as a point of reference for quantitative evaluation and comparison of different automatic estimation methods for BCS is lacking. The main objective of this study was to develop a technique that was able to describe the body shape of cows in a reconstructive way. Images, used to build a benchmark data set for developing an automatic system for BCS, were taken using a camera placed above an exit gate from the milking robot. The camera was positioned at 3 m from the ground and in such a position to capture images of the rear, dorsal pelvic, and loin area of cows. The BCS of each cow was estimated on site by 2 technicians and associated to the cow images. The benchmark data set contained 286 images with associated BCS, anatomical points, and shapes. It was used for quantitative evaluation. A set of example cow body shapes was created. Linear and polynomial kernel principal component analysis was used to reconstruct shapes of cows using a linear combination of basic shapes constructed from the example database. In this manner, a cow's body shape was described by considering her variability from the average shape. The method produced a compact description of the shape to be used for automatic estimation of BCS. Model validation showed that the polynomial model proposed in this study performs better (error=0.31) than other state-of-the-art methods in estimating BCS even at the
The relationship between the stomatognathic system and body posture
Antonino Cuccia; Carola Caradonna
2009-01-01
In recent years, many researchers have investigated the various factors that can influence body posture: mood states, anxiety, head and neck positions, oral functions (respiration, swallowing), oculomotor and visual systems, and the inner ear. Recent studies indicate a role for trigeminal afferents on body posture, but this has not yet been demonstrated conclusively. The present study aims to review the papers that have shown a relationship between the stomatognathic system and body posture. ...
Auto-measuring System of 3- Dimensional Human Body
Institute of Scientific and Technical Information of China (English)
李勇; 尚保平; 付小莉; 尚会超
2001-01-01
To realize the automation of fashion industry measuring,designing and manufacturing, the auto-measurement of 3D size of human body is of great importance. The auto measurement system of 3D human body based on Charge Coupled Devices (CCD) and infrared sensors is presented in this paper. The system can measure the bare size of human body that excludes the effect of clothing quickly and accurately.
Modeling the Collision with Friction of Rigid Bodies
Zabuga, A. G.
2016-09-01
Different models of a perfectly inelastic collision of rigid bodies in plane motion are compared. Formulas for the impact impulses are derived for the Kane-Levinson-Whittaker model based on the kinematic restitution factor, the Routh model based on the kinetic restitution factor, and the Stronge model based on the energy restitution factor. It is shown that these formulas coincide if the collision of rough rigid bodies in plane motion is perfectly inelastic
A Geology Sampling System for Small Bodies
Naids, Adam J.; Hood, Anthony D.; Abell, Paul; Graff, Trevor; Buffington, Jesse
2016-01-01
Human exploration of microgravity bodies is being investigated as a precursor to a Mars surface mission. Asteroids, comets, dwarf planets, and the moons of Mars all fall into this microgravity category and some are being discussed as potential mission targets. Obtaining geological samples for return to Earth will be a major objective for any mission to a small body. Currently, the knowledge base for geology sampling in microgravity is in its infancy. Humans interacting with non-engineered surfaces in microgravity environment pose unique challenges. In preparation for such missions a team at the NASA Johnson Space Center has been working to gain experience on how to safely obtain numerous sample types in such an environment. This paper describes the type of samples the science community is interested in, highlights notable prototype work, and discusses an integrated geology sampling solution.
A Geology Sampling System for Microgravity Bodies
Hood, Anthony; Naids, Adam
2016-01-01
Human exploration of microgravity bodies is being investigated as a precursor to a Mars surface mission. Asteroids, comets, dwarf planets, and the moons of Mars all fall into this microgravity category and some are been discussed as potential mission targets. Obtaining geological samples for return to Earth will be a major objective for any mission to a microgravity body. Currently the knowledge base for geology sampling in microgravity is in its infancy. Humans interacting with non-engineered surfaces in microgravity environment pose unique challenges. In preparation for such missions a team at the NASA Johnson Space Center has been working to gain experience on how to safely obtain numerous sample types in such an environment. This paper describes the type of samples the science community is interested in, highlights notable prototype work, and discusses an integrated geology sampling solution.
More-Realistic Digital Modeling of a Human Body
Rogge, Renee
2010-01-01
A MATLAB computer program has been written to enable improved (relative to an older program) modeling of a human body for purposes of designing space suits and other hardware with which an astronaut must interact. The older program implements a kinematic model based on traditional anthropometric measurements that do provide important volume and surface information. The present program generates a three-dimensional (3D) whole-body model from 3D body-scan data. The program utilizes thin-plate spline theory to reposition the model without need for additional scans.
Modeling for intra-body communication with bone effect.
Pun, S H; Gao, Y M; Mak, P U; Du, M; Vai, M I
2009-01-01
Intra-body communication (IBC) is a new, different "wireless" communication technique based on the human tissue. This short range "wireless" communication technology provides an alternative solution to wearable sensors, home health system, telemedicine and implanted devices. The development of the IBC enables the possibilities of providing less complexity and convenient communication methodologies for these devices. By regarding human tissue as communication channel, IBC making use of the conductivities properties of human tissue to send electrical signal from transmitter to receiver. In this paper, the authors proposed a new mathematical model for galvanic coupling type IBC based on a human limb. Starting from the electromagnetic theory, the authors treat human tissue as volume conductor, which is in analogous with the bioelectric phenomena analysis. In order to explain the mechanism of galvanic coupling type technique of IBC, applying the quasi-static approximation, the governing equation can be reduced to Laplace Equation. Finally, the analytical model is evaluated with on-body measurement for testing its performance. The comparison result shows that the developed mathematical model can provide good approximation for galvanic coupling type IBC on human limb under low operating frequencies.
DEVELOPMENT OF 2D HUMAN BODY MODELING USING THINNING ALGORITHM
Directory of Open Access Journals (Sweden)
K. Srinivasan
2010-11-01
Full Text Available Monitoring the behavior and activities of people in Video surveillance has gained more applications in Computer vision. This paper proposes a new approach to model the human body in 2D view for the activity analysis using Thinning algorithm. The first step of this work is Background subtraction which is achieved by the frame differencing algorithm. Thinning algorithm has been used to find the skeleton of the human body. After thinning, the thirteen feature points like terminating points, intersecting points, shoulder, elbow, and knee points have been extracted. Here, this research work attempts to represent the body model in three different ways such as Stick figure model, Patch model and Rectangle body model. The activities of humans have been analyzed with the help of 2D model for the pre-defined poses from the monocular video data. Finally, the time consumption and efficiency of our proposed algorithm have been evaluated.
Physiological models of body composition and human obesity
Directory of Open Access Journals (Sweden)
Shapses Sue A
2007-09-01
Full Text Available Abstract Background The body mass index (BMI is the standard parameter for predicting body fat fraction and for classifying degrees of obesity. Currently available regression equations between BMI and fat are based on 2 or 3 parameter empirical fits and have not been validated for highly obese subjects. We attempt to develop regression relations that are based on realistic models of body composition changes in obesity. These models, if valid, can then be extrapolated to the high fat fraction of the morbidly obese. Methods The analysis was applied to 3 compartment (density and total body water measurements of body fat. The data was collected at the New York Obesity Research Center, Body Composition Unit, as part of ongoing studies. A total of 1356 subjects were included, with a BMI range of 17 to 50 for males and 17 to 65 for females. The body composition model assumes that obese subjects can be represented by the sum of a standard lean reference subject plus an extra weight that has a constant adipose, bone and muscle fraction. Results There is marked age and sex dependence in the relationship between BMI and fat fraction. There was no significant difference among Caucasians, Blacks and Hispanics while Asians had significantly greater fat fraction for the same BMI. A linear relationship between BMI and fat fraction provides a good description for men but overestimates the fat fraction in morbidly obese women for whom a non-linear regression should be used. New regression relations for predicting body fat just from experimental measurements of body density are described that are more accurate then those currently used. From the fits to the experimental BMI and density data, a quantitative description of the bone, adipose and muscle body composition of lean and obese subjects is derived. Conclusion Physiologically realistic models of body composition provide both accurate regression relations and new insights about changes in body composition in
Multinucleon Ejection Model for Two Body Current Neutrino Interactions
Energy Technology Data Exchange (ETDEWEB)
Sobczyk, Jan T.; /Fermilab
2012-06-01
A model is proposed to describe nucleons ejected from a nucleus as a result of two-body-current neutrino interactions. The model can be easily implemented in Monte Carlo neutrino event generators. Various possibilities to measure the two-body-current contribution are discussed. The model can help identify genuine charge current quasielastic events and allow for a better determination of the systematic error on neutrino energy reconstruction in neutrino oscillation experiments.
DYNAMIC CHARACTERISTICS ON PRECISION NC LATHE BASED ON MULTI-BODY SYSTEM THEORY
Institute of Scientific and Technical Information of China (English)
Wu Nanxing; Sun Qinghong; Zhang Yonghong; Yu Dongling
2005-01-01
Based on multi-body system theory and the mainshaft system of precision NC lathe as object investigated, it is treated as a coupled rigid-flexible multi-body system which is made up of some rigid and elastic bodies in an especial linking mode. And a dynamic model is established. The problems of computing vibration characteristics are resolved by using multi-body system transfer matrix method. Results show that the mainshaft system of NC lathe is in the stable and reliable working area all the time. The method is simple and easy, the idea is clear. In addition, the method can be easily used and popularized in the other multi-body system.
Directory of Open Access Journals (Sweden)
Francisco Rodríguez-Trelles
1998-12-01
Full Text Available Current efforts to study the biological effects of global change have focused on ecological responses, particularly shifts in species ranges. Mostly ignored are microevolutionary changes. Genetic changes may be at least as important as ecological ones in determining species' responses. In addition, such changes may be a sensitive indicator of global changes that will provide different information than that provided by range shifts. We discuss potential candidate systems to use in such monitoring programs. Studies of Drosophila subobscura suggest that its chromosomal inversion polymorphisms are responding to global warming. Drosophila inversion polymorphisms can be useful indicators of the effects of climate change on populations and ecosystems. Other species also hold the potential to become important indicators of global change. Such studies might significantly influence ecosystem conservation policies and research priorities.
Modeling grain-scale thermoelastic stresses on airless bodies
Molaro, J.; Byrne, S.
2013-12-01
Thermal stress weathering is the mechanical breakdown of rock from expansion and contraction caused by changes in temperature. Damage occurs in the form of microscopic cracks that result from a thermal cycle or thermal shock. This process may play an important role in the evolution of airless landscapes, by contributing to regolith production and crater degradation. Without the presence of an atmosphere, rock surfaces experience very dramatic temperature changes that induce high thermoelastic stresses in the near sub-surface. The thermoelastic behavior of each surface is primarily controlled by its distance to the sun and its solar day length, providing a unique experience on each body. For example, slowly rotating bodies that are close to the sun (such as Mercury) experience a very wide diurnal temperature range. Bodies further from the sun (such as NEAs) have a much smaller range, but rotate quickly and experience rapid temperature 'shocks' during sunrise/set. While many studies suggest stresses induced by these temperature changes may cause rock breakdown, the extent of the damage produced as a result is unknown. In this study, we modeled thermoelastic stresses produced on airless surfaces at the mineral grain scale. Finite Element Analysis of Microstructures (OOF2) is a 2-D finite element modeling program, developed at NIST and designed to help scientists calculate macroscopic properties of real or simulated microstructures. This allows us to model thermal behavior of microstructures with varying grain sizes and thermophysical properties, and to explore the relationship between the spatial and temporal temperature gradients and stress. Using OOF2, we imposed the solar and conductive fluxes calculated by our 1-D thermal model at the surface and at 5mm depth on a microstructure. The microstructure has bulk properties typical of a basalt, and a grain size of ~0.3 mm. We assigned 20% and 80% of the grains a thermal conductivity of 1 and 3 W/mK, respectively. The
Exact phase space functional for two-body systems
Gracia-Bondía, José M
2010-01-01
The determination of the two-body density functional from its one-body density is achieved for Moshinsky's harmonium model, using a phase-space formulation, thereby resolving its phase dilemma. The corresponding sign rules can equivalently be obtained by minimizing the ground-state energy.
Glukharev, K. K.; Morozova, N. I.; Potemkin, B. A.; Solovyev, V. S.; Frolov, K. V.
1973-01-01
A mathematical model of the human body was constructed, under the action of harmonic vibrations, in the 2.5-7 Hz frequency range. In this frequency range, the model of the human body as a vibrating system, with concentrated parameters is considered. Vertical movements of the seat and vertical components of vibrations of the human body are investigated.
DIORAMA Model of Satellite Body Orientation
Energy Technology Data Exchange (ETDEWEB)
Werley, Kenneth Alan [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
2016-03-04
The DIORAMA GPS satellite platform orientation model is described. Satellites need to keep sensors pointed towards the earth and solar panels oriented to face the sun (when not in the earth’s shadow) while they orbit the earth.
A Circuit Model of Real Time Human Body Hydration.
Asogwa, Clement Ogugua; Teshome, Assefa K; Collins, Stephen F; Lai, Daniel T H
2016-06-01
Changes in human body hydration leading to excess fluid losses or overload affects the body fluid's ability to provide the necessary support for healthy living. We propose a time-dependent circuit model of real-time human body hydration, which models the human body tissue as a signal transmission medium. The circuit model predicts the attenuation of a propagating electrical signal. Hydration rates are modeled by a time constant τ, which characterizes the individual specific metabolic function of the body part measured. We define a surrogate human body anthropometric parameter θ by the muscle-fat ratio and comparing it with the body mass index (BMI), we find theoretically, the rate of hydration varying from 1.73 dB/min, for high θ and low τ to 0.05 dB/min for low θ and high τ. We compare these theoretical values with empirical measurements and show that real-time changes in human body hydration can be observed by measuring signal attenuation. We took empirical measurements using a vector network analyzer and obtained different hydration rates for various BMI, ranging from 0.6 dB/min for 22.7 [Formula: see text] down to 0.04 dB/min for 41.2 [Formula: see text]. We conclude that the galvanic coupling circuit model can predict changes in the volume of the body fluid, which are essential in diagnosing and monitoring treatment of body fluid disorder. Individuals with high BMI would have higher time-dependent biological characteristic, lower metabolic rate, and lower rate of hydration.
Energy Technology Data Exchange (ETDEWEB)
Martinez, Nicole E. [Department of Environmental and Engineering Sciences, Clemson University, Clemson, South Carolina, 29634 (United States); Johnson, Thomas E.; Ruedig, Elizabeth; Pinder, John E. III [Department of Environmental and Radiological Health Sciences, Colorado State University, 1681 Campus Delivery, Fort Collins, Colorado, 80523 (United States)
2014-07-01
. Organs were modeled using detailed tissue composition data for rainbow trout acquired by ICP-MS. We consider the dose rates to the thyroid, GI-tract, and liver of rainbow trout from uptake of iodine-131, where the concentrations of {sup 131}I in these organs have been determined for the first 32 days following an {sup 131}I release into the freshwater system. The largest average organ dose rates were for the thyroid, which ranged up to 0.6 mGy d{sup -1}. Preliminary results suggest significant differences between the phantom types for both whole body and organ dose rates, and agree well with previous work which has proposed 104 as the maximum deviation between whole body and organ dose rates. (authors)
Modeling for Deformable Body and Motion Analysis: A Review
Directory of Open Access Journals (Sweden)
Hailang Pan
2013-01-01
Full Text Available This paper surveys the modeling methods for deformable human body and motion analysis in the recent 30 years. First, elementary knowledge of human expression and modeling is introduced. Then, typical human modeling technologies, including 2D model, 3D surface model, and geometry-based, physics-based, and anatomy-based approaches, and model-based motion analysis are summarized. Characteristics of these technologies are analyzed. The technology accumulation in the field is outlined for an overview.
Revised scaling variables in systems with many-body interactions
Goldstein, Raymond E.; Parola, Alberto
1987-06-01
Thermodynamic perturbation theory and the Kirkwood-Salsburg correlation function identities are used to study nearest-neighbor lattice gases with certain weak symmetry-breaking many-body interactions. It is shown that such systems may be mapped onto symmetric models by the introduction of suitable effective interactions and a shifted chemical potential, both of which depend explicitly on the temperature and fugacity of the original model. In the critical region, such a thermodynamic-state dependence implies the existence of a thermal scaling field which depends on the bare chemical potential, and this ``field mixing'' leads to a breakdown in the classical law of the rectilinear diameter. These results give a microscopic interpretation to a field-theoretic renormalization-group analysis which derives such a diameter singularity from the presence of terms cubic and higher in the order parameter and its gradients in an asymmetric Landau-Ginzburg-Wilson Hamiltonian. For a primarily repulsive three-body potential like the Axilrod-Teller interaction in classical insulating fluids, and in comparison with recent experiments, the analysis correctly describes the observed trends in the critical and near-critical behavior of the diameters with increasing particle polarizability.
A system and method for imaging body areas
Goethals, F.P.C.
2013-01-01
The invention relates to a system for imaging one or more external human body areas comprising a photographic device configured to acquire, store and output an image or images of the one or more body areas. The invention also relates to a method for determining a probable disease state of an externa
Collisions of Constrained Rigid Body Systems with Friction
Directory of Open Access Journals (Sweden)
Haijun Shen
1998-01-01
Full Text Available A new approach is developed for the general collision problem of two rigid body systems with constraints (e.g., articulated systems, such as massy linkages in which the relative tangential velocity at the point of contact and the associated friction force can change direction during the collision. This is beyond the framework of conventional methods, which can give significant and very obvious errors for this problem, and both extends and consolidates recent work. A new parameterization and theory characterize if, when and how the relative tangential velocity changes direction during contact. Elastic and dissipative phenomena and different values for static and kinetic friction coefficients are included. The method is based on the explicitly physical analysis of events at the point of contact. Using this method, Example 1 resolves (and corrects a paradox (in the literature of the collision of a double pendulum with the ground. The method fundamentally subsumes other recent models and the collision of rigid bodies; it yields the same results as conventional methods when they would apply (Example 2. The new method reformulates and extends recent approaches in a completely physical context.
Automatic Modeling of Virtual Humans and Body Clothing
Institute of Scientific and Technical Information of China (English)
Nadia Magnenat-Thalmann; Hyewon Seo; Frederic Cordier
2004-01-01
Highly realistic virtual human models are rapidly becoming commonplace in computer graphics.These models, often represented by complex shape and requiring labor-intensive process, challenge the problem of automatic modeling. The problem and solutions to automatic modeling of animatable virtual humans are studied. Methods for capturing the shape of real people, parameterization techniques for modeling static shape (the variety of human body shapes) and dynamic shape (how the body shape changes as it moves) of virtual humans are classified, summarized and compared. Finally, methods for clothed virtual humans are reviewed.
Biostereometric Data Processing In ERGODATA: Choice Of Human Body Models
Pineau, J. C.; Mollard, R.; Sauvignon, M.; Amphoux, M.
1983-07-01
The definition of human body models was elaborated with anthropometric data from ERGODATA. The first model reduces the human body into a series of points and lines. The second model is well adapted to represent volumes of each segmentary element. The third is an original model built from the conventional anatomical points. Each segment is defined in space by a tri-angular plane located with its 3-D coordinates. This new model can answer all the processing possibilities in the field of computer-aided design (C.A.D.) in ergonomy but also biomechanics and orthopaedics.
Institute of Scientific and Technical Information of China (English)
李奇; 吴定俊; 邵长宇
2011-01-01
The car-body of a railway vehicle is flexible in nature.Car-body flexibility is considered while the wheel-sets and the bogies of a railway vehicle are regarded as rigid bodies in the proposed vehicle-bridge dynamic interaction analysis method.The vehicle is considered as a spatial structure supported on the wheel-rail interface through Hertz nonlinear spring.The wheel-sets and bogies are established by rigid beam elements coded in general finite element software.The car-body is modeled by flexible beam elements, and linear stiffness of the primary and the secondary suspensions is modeled by spring elements in the same software.The damping forces of the suspensions and the wheel-rail interaction forces on wheel-sets are treated as pseudo forces acted on the vehicle subsystem.The wheel-rail interaction forces on the rails are similarly treated as pseudo forces acted on the bridge subsystem.Mode analyses are conducted based on finite element models of the vehicle and the bridge.And then mode superposition method associated with pseudo force treatment is applied to establish equations of motion of the coupling vehicle-bridge system.An iterative scheme is used to solve the equations of the system.The proposed method is firstly verified by a numerical example, and then the vibration of the car-body with different flexibility is numerically simulated when high speed train traverses multi-span simply supported bridges.The car-body acceleration is found to be underestimated if its flexibility is not considered, especially when flexible car-body resonance phenomena occur.Nevertheless, the bridge acceleration is hardly affected by flexible car-body vibration.%铁路车辆车体的柔性是其固有属性.假设车体为柔性体而轮对、构架为刚性体,并将车辆视为通过赫兹接触弹簧支撑在轮轨接触界面之上的空间结构.在通用有限元软件中采用刚度极大的梁单元建立轮对和构架模型,而采用刚度适当的梁单元建立车
Directory of Open Access Journals (Sweden)
Partha Pratim Ray
2013-10-01
Full Text Available Nanonetwork design and analysis has become a very interesting topic in recent years. Though this area of research is in its formative stage, it definitely posses a strong integrity in finding out numerous applications in medical and allied sciences. Nanonetworking is indeed a nature built foundation which comprises human intra body communications. Somatosensory system is the one of the critical and must have systems of human body. This literature concentrates on the body discriminative touch and proprioception mechanism of somatosensory system. This particular system is well architecture by medial lemniscal pathway, in human body for transduction of touch and proprioceptive information. This paper seeks out the novel communication channel model of somatosensory system. The working principle of the channel model is established by an equivalent Moore machine. A novel algorithm MLP is proposed after its name, medial lemniscal pathway. A novel naomachine and appropriate processing unit are also devised, based on the automaton.
Generalized parton distributions of few body systems
Scopetta, S
2007-01-01
The relevance of measuring Generalized Parton Distributions (GPDs) for few nucleon systems is illustrated. An approach which permits to calculate the GPDs of hadrons made of composite constituents by proper convolutions is described. The application of the method to the nucleon target, assumed to be made of composite constituents is reviewed. Calculations of GPDs for few nucleon systems are summarized, with special emphasis to the $^3$He target.
Stochastic modeling of uncertain mass characteristics in rigid body dynamics
Richter, Lanae A.; Mignolet, Marc P.
2017-03-01
This paper focuses on the formulation, assessment, and application of a modeling strategy of uncertainty on the mass characteristics of rigid bodies, i.e. mass, position of center of mass, and inertia tensor. These characteristics are regrouped into a 4×4 matrix the elements of which are represented as random variables with joint probability density function derived following the maximum entropy framework. This stochastic model is first shown to satisfy all properties expected of the mass and tensor of inertia of rigid bodies. Its usefulness and computational efficiency are next demonstrated on the behavior of a rigid body in pure rotation exhibiting significant uncertainty in mass distribution.
Regularities of many-body systems interacting by a two-body random ensemble
Energy Technology Data Exchange (ETDEWEB)
Zhao, Y.M. [Department of Physics, Shanghai Jiao-Tong University, Shanghai 200030 (China) and Cyclotron Center, Institute of Physical and Chemical Research - RIKEN, Hirosawa 2-1, Wako-shi, Saitama 351-0198 (Japan) and Department of Physics, Southeast University, Nanjing 210018 (China)]. E-mail: ymzhao@riken.jp; Arima, A. [Science Museum, Japan Science Foundation, 2-1 Kitanomaru-Koen, Chiyodaku, Tokyo 102-0091 (Japan); Yoshinaga, N. [Department of Physics, Saitama University, Saitama 338-0625 (Japan)
2004-10-01
The ground states of all even-even nuclei have angular momentum, I, equal to zero, I=0, and positive parity, {pi}=+. This feature was believed to be a consequence of the attractive short-range interaction between nucleons. However, in the presence of two-body random interactions, the predominance of I{pi}=0+ ground states (0 g.s.) was found to be robust both for bosons and for an even number of fermions. For simple systems, such as d bosons, sp bosons, sd bosons, and a few fermions in single-j shells for small j, there are a few approaches to predict and/or explain spin I ground state (I g.s.) probabilities. An empirical approach to predict I g.s. probabilities is available for general cases, such as fermions in a single-j (j>72) or many-j shells and various boson systems, but a more fundamental understanding of the robustness of 0 g.s. dominance is still out of reach. Further interesting results are also reviewed concerning other robust phenomena of many-body systems in the presence of random two-body interactions, such as the odd-even staggering of binding energies, generic collectivity, the behavior of average energies, correlations, and regularities of many-body systems interacting by a displaced two-body random ensemble.
Body circumferences: clinical implications emerging from a new geometric model
Directory of Open Access Journals (Sweden)
Gallagher Dympna
2008-10-01
Full Text Available Abstract Background Body volume expands with the positive energy balance associated with the development of adult human obesity and this "growth" is captured by two widely used clinical metrics, waist circumference and body mass index (BMI. Empirical correlations between circumferences, BMI, and related body compartments are frequently reported but fail to provide an important common conceptual foundation that can be related to key clinical observations. A two-phase program was designed to fill this important gap: a geometric model linking body volume with circumferences and BMI was developed and validated in cross-sectional cohorts; and the model was applied to the evaluation of longitudinally monitored subjects during periods of voluntary weight loss. Concepts emerging from the developed model were then used to examine the relations between the evaluated clinical measures and body composition. Methods Two groups of healthy adults (n = 494 and 1499 were included in the cross-sectional model development/testing phase and subjects in two previous weight loss studies were included in the longitudinal model evaluation phase. Five circumferences (arm, waist, hip, thigh, and calf; average of sum, C, height (H, BMI, body volume (V; underwater weighing, and the volumes of major body compartments (whole-body magnetic resonance imaging were measured. Results The evaluation of a humanoid geometric model based a cylinder confirmed that V derived from C and H was highly correlated with measured V [R2 both males and females, 0.97; p 0.5. The scaling of individual circumferences to V/H varied, with waist the highest (V/H~0.6 and calf the lowest (V/H~0.3, indicating that the largest and smallest between-subject "growth" with greater body volume occurs in the abdominal area and lower extremities, respectively. A stepwise linear regression model including all five circumferences2 showed that each contributed independently to V/H. These cross
Choreography and Gravitational Waves for 2-BODY and 3-BODY Gravitating Systems
Asada, Hideki
In the framework of general relativity, we discuss choreographic solutions for the three-body problem, where a solution is called choreographic if every massive particles move periodically in a single closed orbit. In general relativity, the periastron shift prohibits a binary system from orbiting in a single closed curve. Remarkably, a "figure-eight" solution is shown to be choreographic even at the PN approximation by carefully examining initial conditions. Next, gravitational waves for two- and three-body gravitating systems are discussed as an inverse problem. It is shown that quadrupole waveforms cannot distinguish these sources at particular configurations, especially through extending the definition of the chirp mass to such a three-body system. Finally, we present a conjecture on N particles for classification of sources with multipolar waveforms.
Body image and adolescence: A behavioral impairment model.
Senín-Calderón, Cristina; Rodríguez-Testal, Juan F; Perona-Garcelán, Salvador; Perpiñá, Conxa
2017-02-01
Adolescence is a period marked by important physical and social changes that can lead to a negative body image. The purpose of this study was to find a model enabling the appearance of behavioral impairment related to body image (restrictions, avoidance, and checking) to be predicted by body image attitudes (concern or Appearance Orientation, and dissatisfaction or Appearance Evaluation), Gender, emotional symptomatology, self-consciousness, ideas of reference (IR) and age. A total of 661 participants (67.47% girls) with an average age of 17.14 years (SD=2.34) filled in the GHQ-28, SCS on self-consciousness, REF referential thinking scale, MBSRQ (AO and AE), and BIAQ. A partial mediation model was found for IR, age and depressive symptomatology between dissatisfaction and concern about body image and Gender, to behavioral impairment related to body image. The results found suggest that age, depressive symptomatology, and IR may be mediator variables in the relationship between dissatisfaction and concern about body image, on body image behavioral impairment. This relationship implies a severity to be considered in intervention and monitoring of body image behavioral impairments in adolescents.
A long term model of circulation. [human body
White, R. J.
1974-01-01
A quantitative approach to modeling human physiological function, with a view toward ultimate application to long duration space flight experiments, was undertaken. Data was obtained on the effect of weightlessness on certain aspects of human physiological function during 1-3 month periods. Modifications in the Guyton model are reviewed. Design considerations for bilateral interface models are discussed. Construction of a functioning whole body model was studied, as well as the testing of the model versus available data.
Investigation of $^{23}$N in a three-body model
Zhang, Liuyang; Lyu, Mengjiao; Ji, Chen
2015-01-01
The neutron-drip-line nucleus $^{23}$N is investigated in a three-body model consisting of a $^{21}$N core and two valence neutrons. By solving the Faddeev equations with the realistic neutron-neutron potentials and the neutron-core potentials, we calculate the ground state properties of $^{23}$N and also find that there is a new excited state with two-neutron separation energy at about 0.18 MeV. The properties, such as the two-neutron separation energies, are obtained with a good agreement with experiments. By calculating the root-mean-square matter radii, the average distances between the valence neutrons, and the average distances between the core and the center-of-mass of the neutron pair, we show that the excited state of $^{23}$N has a clear halo structure. The correlation density distributions of the three-body system are also calculated to analyze its geometric configuration. At last, we find that the excited state of $^{23}$N has a very small binding energy, a large radius and distribution, and a tri...
Introduction to Integrable Many-Body Systems II
Šamaj, Ladislav
2010-04-01
This is the second part of a three-volume introductory course about integrable systems of interacting bodies. The models of interest are quantum spin chains with nearest-neighbor interactions between spin operators, in particular Heisenberg spin-1/2 models. The Ising model in a transverse field, expressible as a quadratic fermion form by using the Jordan-Wigner transformation, is the subject of Sect. 12. The derivation of the coordinate Bethe ansatz for the XXZ Heisenberg chain and the determination of its absolute ground state in various regions of the anisotropy parameter are presented in Sect. 13. The magnetic properties of the ground state are explained in Sect. 14. Sect. 15 concerns excited states and the zero-temperature thermodynamics of the XXZ model. The thermodynamics of the XXZ Heisenberg chain is derived on the basis of the string hypothesis in Sect. 16; the thermodynamic Bethe ansatz equations are analyzed in high-temperature and low-temperature limits. An alternative derivation of the thermodynamics without using strings, leading to a non-linear integral equation determining the free energy, is the subject of Sect. 17. A nontrivial application of the Quantum Inverse Scattering method to the fully anisotropic XYZ Heisenberg chain is described in Sect. 18. Sect. 19 deals with integrable cases of isotropic spin chains with an arbitrary spin.
Nonlocality in many-body quantum systems detected with two-body correlators
Energy Technology Data Exchange (ETDEWEB)
Tura, J., E-mail: jordi.tura@icfo.es [ICFO—Institut de Ciencies Fotoniques, Mediterranean Technology Park, 08860 Castelldefels (Barcelona) (Spain); Augusiak, R.; Sainz, A.B. [ICFO—Institut de Ciencies Fotoniques, Mediterranean Technology Park, 08860 Castelldefels (Barcelona) (Spain); Lücke, B.; Klempt, C. [Institut für Quantenoptik, Leibniz Universität Hannover, Welfengarten 1, D-30167 Hannover (Germany); Lewenstein, M.; Acín, A. [ICFO—Institut de Ciencies Fotoniques, Mediterranean Technology Park, 08860 Castelldefels (Barcelona) (Spain); ICREA—Institució Catalana de Recerca i Estudis Avançats, Lluis Campanys 3, 08010 Barcelona (Spain)
2015-11-15
Contemporary understanding of correlations in quantum many-body systems and in quantum phase transitions is based to a large extent on the recent intensive studies of entanglement in many-body systems. In contrast, much less is known about the role of quantum nonlocality in these systems, mostly because the available multipartite Bell inequalities involve high-order correlations among many particles, which are hard to access theoretically, and even harder experimentally. Standard, “theorist- and experimentalist-friendly” many-body observables involve correlations among only few (one, two, rarely three...) particles. Typically, there is no multipartite Bell inequality for this scenario based on such low-order correlations. Recently, however, we have succeeded in constructing multipartite Bell inequalities that involve two- and one-body correlations only, and showed how they revealed the nonlocality in many-body systems relevant for nuclear and atomic physics [Tura et al., Science 344 (2014) 1256]. With the present contribution we continue our work on this problem. On the one hand, we present a detailed derivation of the above Bell inequalities, pertaining to permutation symmetry among the involved parties. On the other hand, we present a couple of new results concerning such Bell inequalities. First, we characterize their tightness. We then discuss maximal quantum violations of these inequalities in the general case, and their scaling with the number of parties. Moreover, we provide new classes of two-body Bell inequalities which reveal nonlocality of the Dicke states—ground states of physically relevant and experimentally realizable Hamiltonians. Finally, we shortly discuss various scenarios for nonlocality detection in mesoscopic systems of trapped ions or atoms, and by atoms trapped in the vicinity of designed nanostructures.
Signal measurement system for intra-body communication using optical isolation method
Matsumoto, Kazuki; Katsuyama, Jun; Sugiyama, Ryo; Takizawa, Yasuaki; Ishii, Seita; Shinagawa, Mitsuru; Kado, Yuichi
2014-09-01
In this paper, we describe an induced signal measurement on the human body for developing a high-performance transceiver of an intra-body communication system. It is important to isolate awearable transceiver from an electrical instrument for precise measurement. We have developed a probe system using an optical isolation method including a laser diode, photo-diode, and optical fiber. The probe system can be successfully applied to the precise measurement of a receiving signal power at a wearable transceiver. We verify that the experimental results agree with the simulation results based on our previous channel model of intra-body communication.
Three-body model for neutron-halo nuclei
Institute of Scientific and Technical Information of China (English)
无
2008-01-01
The neutron-halo nuclei,11Li,14Be,and 17B,are studied in the three-body model.The Yukawa interaction is used to describe the interaction of the two-body subsystem.For given parameters of the two-body interaction,the properties of these neutron-halo nuclei are calculated with the Faddeev equations and the results are compared with those in the variational method.It is shown that the method of the Faddeev equations is more accurate.Then the dependencies of the two-and three-body energies on the parameters are studied. We find numerically that two-and three-body correlations differ greatly from each other with the variation of the intrinsic force range.
Efimov physics in heteronuclear four-body systems.
Wang, Yujun; Laing, W Blake; von Stecher, Javier; Esry, B D
2012-02-17
We study three- and four-body Efimov physics in a heteronuclear atomic system with three identical heavy bosonic atoms and one light atom. We show that exchange of the light atom between the heavy atoms leads to both three- and four-body features in the low-energy inelastic rate constants that trace to the Efimov effect. Further, the effective interaction generated by this exchange can provide an additional mechanism for control in ultracold experiments. Finally, we find that there is no true four-body Efimov effect-that is, no infinite number of four-body states in the absence of two- and three-body bound states-resolving a decades-long controversy.
Numerical Modeling of Electromagnetic Field Effects on the Human Body
Directory of Open Access Journals (Sweden)
Zuzana Psenakova
2006-01-01
Full Text Available Interactions of electromagnetic field (EMF with environment and with tissue of human beings are still under discussion and many research teams are investigating it. The human simulation models are used for biomedical research in a lot of areas, where it is advantage to replace real human body (tissue by the numerical model. Biological effects of EMF are one of the areas, where numerical models are used with many advantages. On the other side, this research is very specific and it is always quite hard to simulate realistic human tissue. This paper deals with different possibilities of numerical modelling of electromagnetic field effects on the human body (especially calculation of the specific absorption rate (SAR distribution in human body and thermal effect.
Accelerator-feasible N -body nonlinear integrable system
Danilov, V.; Nagaitsev, S.
2014-12-01
Nonlinear N -body integrable Hamiltonian systems, where N is an arbitrary number, have attracted the attention of mathematical physicists for the last several decades, following the discovery of some number of these systems. This paper presents a new integrable system, which can be realized in facilities such as particle accelerators. This feature makes it more attractive than many of the previous such systems with singular or unphysical forces.
Rapid three-dimensional chromoscan system of body surface based on digital fringe projection
Wei, Bin; Liang, Jin; Li, Jie; Ren, Maodong
2015-09-01
This paper proposes a rapid body scanning system that uses optical digital fringe projection method. Twelve cameras and four digital projectors are placed around the human body from four different directions, so that the body surface threedimensional( 3D) point cloud data can be scanned in 5~8 seconds. It can overcome many difficulties in a traditional measurement method, such as laser scanning causes damage to human eye and low splicing accuracy using structured white light scanning system. First, an accurate calibration method based on close-range photogrammetry, is proposed and verified for calibrating the twelve cameras and the four digital projectors simultaneously, where a 1m×2m plate as calibration target with feature points pasted on its two-sides is used. An experiment indicates that the proposed calibration method, with a re-projection error less than 0.05pixels, has a considerable accuracy. The whole 3D body surface color point cloud data can be measured without splice different views of point cloud, because of the high accuracy calibration results. Then, in order to measure the whole body point cloud data with high accuracy, a combination of single and stereo camera measuring method, based on digital fringe projection, has presented to calculating 3D point cloud data. At last, a novel body chromoscan system is developed and a human body 3D digital model was scanned, by which a physical body model was manufactured using 3D printing technology.
Ultracold atoms for simulation of many body quantum systems
Hutchinson, David A. W.
2017-01-01
Feynman famously proposed simulating quantum physics using other, better controlled, quantum systems. This vision is now a reality within the realm of ultracold atomic physics. We discuss how these systems can be used to simulate many body physics, concentrating the Berezinskii-Kosterlitz-Thouless transition in 2D physics and the role of disorder.
Thermal history modeling of the H chondrite parent body
Henke, Stephan; Trieloff, Mario; Schwarz, Winfried H; Kleine, Thorsten
2012-01-01
The cooling histories of individual meteorites can be empirically reconstructed by using ages from different radioisotopic chronometers with distinct closure temperatures. For a group of meteorites derived from a single parent body such data permit the reconstruction of the cooling history and properties of that body. Particularly suited are H chondrites because precise radiometric ages over a wide range of closure temperatures are available. A thermal evolution model for the H chondrite parent body is constructed by using all H chondrites for which at least three different radiometric ages are available. Several key parameters determining the thermal evolution of the H chondrite parent body and the unknown burial depths of the H chondrites are varied until an optimal fit is obtained. The fit is performed by an 'evolution algorithm'. Empirical data for eight samples are used for which radiometric ages are available for at least three different closure temperatures. A set of parameters for the H chondrite pare...
Institute of Scientific and Technical Information of China (English)
贺少华; 谢最伟; 吴新跃
2011-01-01
A new method was proposed for shock response modeling and computing for a planar multi-rigid-flexible body system by integrating the transfer matrix technique with its flexibility and higher computational efficiency.Adopting Newmark-β algorithm to linearize higher order terms in dynamic equations and modal shapes to express flexible body deformation, extended transfer matrixes of general rigid-bodies and special rigid bodies ( rigid homogeneous rectangular plate, rectangular sheet plate with elastic supports), general flexible-bodies and special flexible bodies ( Euler-Bernouui beam) in systems under base-transferred shock were established.The shock excitations included both translational and rotational components.Numerical iterative algorithm program based on Newmark-β method was also given.With an engineering example, the accuracy of this proposed method was verified by finite element method.The results show that the contribution of the rotational components of shock to the overall response can not be ignored.Although the objective of this study was a planar multi-rigid-flexible system, the proposed method could easily be extended to three-dimensional cases.%结合传递矩阵方法建模灵活和计算效率高的优点,提出了一种基于"传递矩阵"概念的多体系统冲击响应建模和计算方法.以受基础冲击的平面多刚柔系统为研究对象,采用Newmark-β法对元件的方程高阶项进行线性化,用模态方法处理柔体的变形,建立了一般刚体和典型刚体(刚性均质矩形板、带弹性支撑的刚性均质矩形薄板)、一般柔体和典型柔体(Euler-Bernouni梁)的冲击扩展传递矩阵,冲击激励包含平动和转动两种成分,给出了基于Newmark-β法的系统响应数值迭代求解算法程序.用一个工程实例,通过与有限元方法的对比,验证了方法的准确性,得出了转动冲击激励成分对总体响应的贡献不能忽略的结论.方法的研究对象虽然只是平面多
RELIABLE ROBUST CONTROLLER FOR HALF-CAR ACTIVE SUSPENSION SYSTEMS BASED ON HUMAN-BODY DYNAMICS
Directory of Open Access Journals (Sweden)
Mohammad Gudarzi
2016-08-01
Full Text Available The paper investigates a non-fragile robust control strategy for a half-car active suspension system considering human-body dynamics. A 4-DoF uncertain vibration model of the driver’s body is combined with the car’s model in order to make the controller design procedure more accurate. The desired controller is obtained by solving a linear matrix inequality formulation. Then the performance of the active suspension system with the designed controller is compared to the passive one in both frequency and time domain simulations. Finally, the effect of the controller gain variations on the closed-loop system performance is investigated numerically.
Cellier, Francois E.
1991-01-01
A comprehensive and systematic introduction is presented for the concepts associated with 'modeling', involving the transition from a physical system down to an abstract description of that system in the form of a set of differential and/or difference equations, and basing its treatment of modeling on the mathematics of dynamical systems. Attention is given to the principles of passive electrical circuit modeling, planar mechanical systems modeling, hierarchical modular modeling of continuous systems, and bond-graph modeling. Also discussed are modeling in equilibrium thermodynamics, population dynamics, and system dynamics, inductive reasoning, artificial neural networks, and automated model synthesis.
Loizzo, Joseph J
2016-06-01
Meditation research has begun to clarify the brain effects and mechanisms of contemplative practices while generating a range of typologies and explanatory models to guide further study. This comparative review explores a neglected area relevant to current research: the validity of a traditional central nervous system (CNS) model that coevolved with the practices most studied today and that provides the first comprehensive neural-based typology and mechanistic framework of contemplative practices. The subtle body model, popularly known as the chakra system from Indian yoga, was and is used as a map of CNS function in traditional Indian and Tibetan medicine, neuropsychiatry, and neuropsychology. The study presented here, based on the Nalanda tradition, shows that the subtle body model can be cross-referenced with modern CNS maps and challenges modern brain maps with its embodied network model of CNS function. It also challenges meditation research by: (1) presenting a more rigorous, neural-based typology of contemplative practices; (2) offering a more refined and complete network model of the mechanisms of contemplative practices; and (3) serving as an embodied, interoceptive neurofeedback aid that is more user friendly and complete than current teaching aids for clinical and practical applications of contemplative practice.
Measuring entanglement entropy in a quantum many-body system.
Islam, Rajibul; Ma, Ruichao; Preiss, Philipp M; Tai, M Eric; Lukin, Alexander; Rispoli, Matthew; Greiner, Markus
2015-12-01
Entanglement is one of the most intriguing features of quantum mechanics. It describes non-local correlations between quantum objects, and is at the heart of quantum information sciences. Entanglement is now being studied in diverse fields ranging from condensed matter to quantum gravity. However, measuring entanglement remains a challenge. This is especially so in systems of interacting delocalized particles, for which a direct experimental measurement of spatial entanglement has been elusive. Here, we measure entanglement in such a system of itinerant particles using quantum interference of many-body twins. Making use of our single-site-resolved control of ultracold bosonic atoms in optical lattices, we prepare two identical copies of a many-body state and interfere them. This enables us to directly measure quantum purity, Rényi entanglement entropy, and mutual information. These experiments pave the way for using entanglement to characterize quantum phases and dynamics of strongly correlated many-body systems.
Nonlinear MPC and MHE for Mechanical Multi-Body Systems with Application to Fast Tethered Airplanes
2012-01-01
International audience; Mechanical applications often require a high control frequency to cope with fast dynamics. The control frequency of a nonlinear model predictive controller depends strongly on the symbolic complexity of the equations modeling the system. The symbolic complexity of the model equations for multi-body mechanical systems can often be dramatically reduced by using representations based on non-minimal coordinates, which result in index-3 differential-algebraic equations (DAE...
Instabilities on crystal surfaces: The two-component body-centered solid-on-solid model
Carlon, E.; van Beijeren, H.; Mazzeo, G.
1996-01-01
The free energy of crystal surfaces that can be described by the two-component body-centered solid-on-solid model has been calculated in a mean-field approximation. The system may model ionic crystals with a bcc lattice structure (for instance CsCl). Crossings between steps are energetically favored
Identification of Motive Forces on the Whole Body System during Walking
Directory of Open Access Journals (Sweden)
Raghdan J. AlKhoury
2010-01-01
Full Text Available Motive forces by muscles are applied to different parts of the human body in a periodic fashion when walking at a uniform rate. In this study, the whole human body is modeled as a multidegree of freedom (MDOF system with seven degrees of freedom. In view of the changing contact conditions with the ground due to alternating feet movements, the system under study is considered piecewise time invariant for each half-period when one foot is in contact with the ground. Forces transmitted from the body to the ground while walking at a normal pace are experimentally measured and numerically simulated. Fourth-order Runge-Kutta method is employed to numerically simulate the forces acting on different masses of the body. An optimization problem is formulated with the squared difference between the measured and simulated forces transmitted to the ground as the objective function, and the motive forces on the body masses as the design variables to solve.
Nuclear electric dipole moment of three-body systems
Song, Young-Ho; Lazauskas, Rimantas; Gudkov, Vladimir
2013-01-01
Background: The existence of the electric dipole moment (EDM) of stable nuclei would be a direct evidence of the time reversal invariance violation (TRIV). Therefore, its measurement could be considered as a complement to the search for neutron and atomic EDMs.Purpose: To clarify theoretical issues related to calculations of EDMs in many-body systems we calculated the EDMs of the simplest nuclei.Method: For calculations of three-nucleon systems EDMs we used TRIV potentials based on the meson exchange theory, as well as the ones derived by using effective field theories (EFT) with and without explicit pions. Nuclear wave functions were obtained by solving Faddeev equations in configuration space for the complete Hamiltonians comprising both TRIV and realistic strong interactions.Results: The expressions for EDMs of 3He and 3H are given in terms of meson exchange couplings and low energy constants of EFT potentials.Conclusions: The obtained results are compared with the previous calculations of 3He EDM and with time reversal invariance violating effects in neutron-deuteron scattering. The model dependence on strong interactions is discussed.
The relationship between the stomatognathic system and body posture.
Cuccia, Antonino; Caradonna, Carola
2009-01-01
In recent years, many researchers have investigated the various factors that can influence body posture: mood states, anxiety, head and neck positions, oral functions (respiration, swallowing), oculomotor and visual systems, and the inner ear. Recent studies indicate a role for trigeminal afferents on body posture, but this has not yet been demonstrated conclusively. The present study aims to review the papers that have shown a relationship between the stomatognathic system and body posture. These studies suggest that tension in the stomatognathic system can contribute to impaired neural control of posture. Numerous anatomical connections between the stomatognathic system's proprioceptive inputs and nervous structures are implicated in posture (cerebellum, vestibular and oculomotor nuclei, superior colliculus). If the proprioceptive information of the stomatognathic system is inaccurate, then head control and body position may be affected. In addition, the present review discusses the role the myofascial system plays in posture. If confirmed by further research, these considerations can improve our understanding and treatment of muscular-skeletal disorders that are associated with temporomandibular joint disorders, occlusal changes, and tooth loss.
The relationship between the stomatognathic system and body posture
Directory of Open Access Journals (Sweden)
Antonino Cuccia
2009-01-01
Full Text Available In recent years, many researchers have investigated the various factors that can influence body posture: mood states, anxiety, head and neck positions, oral functions (respiration, swallowing, oculomotor and visual systems, and the inner ear. Recent studies indicate a role for trigeminal afferents on body posture, but this has not yet been demonstrated conclusively. The present study aims to review the papers that have shown a relationship between the stomatognathic system and body posture. These studies suggest that tension in the stomatognathic system can contribute to impaired neural control of posture. Numerous anatomical connections between the stomatognathic system's proprioceptive inputs and nervous structures are implicated in posture (cerebellum, vestibular and oculomotor nuclei, superior colliculus. If the proprioceptive information of the stomatognathic system is inaccurate, then head control and body position may be affected. In addition, the present review discusses the role the myofascial system plays in posture. If confirmed by further research, these considerations can improve our understanding and treatment of muscular-skeletal disorders that are associated with temporomandibular joint disorders, occlusal changes, and tooth loss.
Few-Body Systems in Low-Dimensional Geometries
DEFF Research Database (Denmark)
Volosniev, Artem
2013-01-01
be applied. For this setup few-body bound structures are found for different polarization an- gles and dipole strengths by using stochastic variational methods. After that a similar analysis is provided for two-dimensional planes filled with dipolar par- ticles. At the end of the thesis, a system......The research in this dissertation is devoted to few-body bound state physics in experimentally relevant systems of trapped atoms and molecules. First, the complexes of tubes containing dipoles are considered. The tubes are assumed to have zero width such that one-dimensional treatment can...
Quasi-three body systems - properties and scattering
Amusia, M Ya
2016-01-01
We investigate systems of three mutually interacting particles with masses of which the inner is much bigger than the intermediate and the latter is much bigger than the outer. Then the three-body problem reduces to the two-body scattering or structure of the light one in the field of the pseudo-nucleus formed by two others. We calculate analytically the properties of considered systems, such as the scattering cross-sections, hyperfine splitting, Auger decay of exited states and Lamb shits, presenting them as expansions in powers of the ratio of light to intermediate particle masses. This ratio is the small parameter of the studied problems.
Tidal interactions - crude body model in dynamical investigations
Gabryszewski, Ryszard
2011-01-01
The paper presents results of investigations of small bodies dynamics in a vicinity of giant planets. We used the most simple body model: gravitationally bounded, rotating contact binary affected by the tidal force acting from a planet. Spin variations of such binaries were extensively studied during planetary close encounters. Two main types of dynamical behaviour were observed: (i) huge but interim fluctuations of the angular velocity and (ii) permanent changes of a rotation during a close approach. The first type is observed mainly for fast rotators, while the second one was encountered in a population of slowly spinning objects with periods longer than 12 hours. Conclusions on usability of such crude physical body models in dynamical investigations and a comparison to previous results were attached. The results allow us to formulate a thesis explaining the phenomenon of creation of the extremely slow rotators and an observational excess of such type of objects.
Body surface mounted biomedical monitoring system using Bluetooth.
Nambu, Masayuki
2007-01-01
Continuous monitoring in daily life is important for the health condition control of the elderly. However, portable or wearable devices need to carry by user on their own will. On the other hand, implantation sensors are not adoptable, because of generic users dislike to insert the any object in the body for monitoring. Therefore, another monitoring system of the health condition to carry it easily is necessary. In addition, ID system is necessary even if the subject live with few families. Furthermore, every measurement system should be wireless system, because not to obstruct the daily life of the user. In this paper, we propose the monitoring system, which is mounted on the body surface. This system will not obstruct the action or behavior of user in daily life, because this system attached the body surface on the back of the user. In addition, this system has wireless communication system, using Bluetooth, and acquired data transfer to the outside of the house via the Internet.
ESA' s novel gravitational modeling of irregular planetary bodies
Ortega, Guillermo
A detailed understanding and modeling of the gravitational modeling is required for realistic investigation of the dynamics of orbits close to irregularly shaped bodies. Gravity field modelling up to a certain maximum spherical harmonic degree N involves N2 unkown spherical harmonic coefficients or complex harmonics. The corresponding number of matrix entries reaches till N4 . For missions like CHAMP, GRACE or GOCE, the maximum degree of resolution is 75, 150 and 300 respectively. Therefore, the number of unknowns for a satellite like GOCE will be around 100.000. Since these missions usually fly for a period of time of several years, the number of observations is huge. Hence, gravity field recovery from these missions is a high demanding task. The classical approaches like spherical expansion of the potential lead generally to a high number of coefficients, which reduce the software computational efficiency of the orbit propagation and which have mostly a limited physical meaning. One of the main targets of the activity is the modelling of asteroids, small moons, and cometary bodies. All celestial bodies are irregular by definition. However, the scope of the activity is broad enough as to be able to use the models and the software in quasy-regular bodies as well. Therefore the models and tools could be used for bodies such as the Moon, Mars, Venus, Deimos, Europa, Eros, Mathilda, and Churyumov-Gerasimenko, etc., being these applications relevant for scientific (Rosetta, Bepi Colombo), exploration (Exo-Mars), NEO mitigation (Don Quijote) and Earth observation (GOCE) missions of ESA.
STUDY ON DYNAMICS, STABILITY AND CONTROL OF MULTI-BODY FLEXIBLE STRUCTURE SYSTEM IN FUNCTIONAL SPACE
Institute of Scientific and Technical Information of China (English)
徐建国; 贾军国
2001-01-01
The dynamics, stability and control problem of a kind of infinite dimensional system are studied in the functional space with the method of modern mathematics. First,the dynamical control model of the distributed parameter system with multi-body flexible and multi-topological structure was established which has damping, gyroscopic parts and constrained damping. Secondly, the necessary and sufficient condition of controllability and observability, the stability theory and asymptotic property of the system were obtained.These results expand the theory of the field about the dynamics and control of the system with multi-body flexible structure, and have important engineering significance.
A Solvable Model of Species Body Mass Evolution
Clauset, Aaron
2008-01-01
We present a quantitative model for the biological evolution of species body masses within large groups of related species, e.g., terrestrial mammals, in which body mass M evolves according to branching (speciating) multiplicative diffusion and an extinction probability that increases logarithmically with mass. We describe this evolution in terms of a convection-diffusion-reaction equation for ln M. The steady-state behavior is in good agreement with empirical data on recent terrestrial mammals, and the time-dependent behavior also agrees with data on extinct mammal species between 95 - 50 million years ago.
Silber, Gerhard
2013-01-01
How can we optimize a bedridden patient’s mattress? How can we make a passenger seat on a long distance flight or ride more comfortable? What qualities should a runner’s shoes have? To objectively address such questions using engineering and scientific methods, adequate virtual human body models for use in computer simulation of loading scenarios are required. The authors have developed a novel method incorporating subject studies, magnetic resonance imaging, 3D-CAD-reconstruction, continuum mechanics, material theory and the finite element method. The focus is laid upon the mechanical in vivo-characterization of human soft tissue, which is indispensable for simulating its mechanical interaction with, for example, medical bedding or automotive and airplane seating systems. Using the examples of arbitrary body support systems, the presented approach provides visual insight into simulated internal mechanical body tissue stress and strain, with the goal of biomechanical optimization of body support systems. ...
Mass-imbalanced Three-Body Systems in Two Dimensions
DEFF Research Database (Denmark)
F. Bellotti, F.; Frederico, T.; T. Yamashita, M.
2013-01-01
We consider three-body systems in two dimensions with zero-range interactions for general masses and interaction strengths. The momentum-space Schr\\"odinger equation is solved numerically and in the Born-Oppenheimer (BO) approximation. The BO expression is derived using separable potentials...
Construction of an exactly solvable model of the many-body problem
Energy Technology Data Exchange (ETDEWEB)
Zettili, N. [King Fahd Univ. of Petrolium and Minerals, Dhahran (Saudi Arabia). Dept. of Phys.]|[Institut de Physique, Universite de Blida, Blida (Algeria); Bouayad, N. [Institut de Physique, Universite de Blida, Blida (Algeria)
1996-11-11
We propose here a new model for the many-body problem that can be solved exactly through the diagonalization of its Hamiltonian. This model, which is founded on a Lie algebra, serves as a useful tool for testing the accuracy of many-body approximation methods. The model consists of a one-dimensional system of two distinguishable sets of fermions interacting via a schematic two-body force. We construct this model`s Hamiltonian by means of vector operators that are the generators of an SO(2,1) group and which satisfy a Lie algebra. We incorporate into the Hamiltonian a symmetry that yields a constant of the motion which, in turn, renders the size of the Hamiltonian matrix finite. The diagonalization of this finitely dimensional matrix gives the exact values of the energy spectrum. (orig.).
Modeling and testing of a tube-in-tube separation mechanism of bodies in space
Michaels, Dan; Gany, Alon
2016-12-01
A tube-in-tube concept for separation of bodies in space was investigated theoretically and experimentally. The separation system is based on generation of high pressure gas by combustion of solid propellant and restricting the expansion of the gas only by ejecting the two bodies in opposite directions, in such a fashion that maximizes generated impulse. An interior ballistics model was developed in order to investigate the potential benefits of the separation system for a large range of space body masses and for different design parameters such as geometry and propellant. The model takes into account solid propellant combustion, heat losses, and gas phase chemical reactions. The model shows that for large bodies (above 100 kg) and typical separation velocities of 5 m/s, the proposed separation mechanism may be characterized by a specific impulse of 25,000 s, two order of magnitude larger than that of conventional solid rockets. It means that the proposed separation system requires only 1% of the propellant mass that would be needed for a conventional rocket for the same mission. Since many existing launch vehicles obtain such separation velocities by using conventional solid rocket motors (retro-rockets), the implementation of the new separation system design can reduce dramatically the mass of the separation system and increase safety. A dedicated experimental setup was built in order to demonstrate the concept and validate the model. The experimental results revealed specific impulse values of up to 27,000 s and showed good correspondence with the model.
Tablet PC Enabled Body Sensor System for Rural Telehealth Applications
Directory of Open Access Journals (Sweden)
Nitha V. Panicker
2016-01-01
Full Text Available Telehealth systems benefit from the rapid growth of mobile communication technology for measuring physiological signals. Development and validation of a tablet PC enabled noninvasive body sensor system for rural telehealth application are discussed in this paper. This system includes real time continuous collection of physiological parameters (blood pressure, pulse rate, and temperature and fall detection of a patient with the help of a body sensor unit and wireless transmission of the acquired information to a tablet PC handled by the medical staff in a Primary Health Center (PHC. Abnormal conditions are automatically identified and alert messages are given to the medical officer in real time. Clinical validation is performed in a real environment and found to be successful. Bland-Altman analysis is carried out to validate the wrist blood pressure sensor used. The system works well for all measurements.
Logarithmic entanglement lightcone in many-body localized systems
Deng, Dong-Ling; Li, Xiaopeng; Pixley, J. H.; Wu, Yang-Le; Das Sarma, S.
2017-01-01
We theoretically study the response of a many-body localized system to a local quench from a quantum information perspective. We find that the local quench triggers entanglement growth throughout the whole system, giving rise to a logarithmic lightcone. This saturates the modified Lieb-Robinson bound for quantum information propagation in many-body localized systems previously conjectured based on the existence of local integrals of motion. In addition, near the localization-delocalization transition, we find that the final states after the local quench exhibit volume-law entanglement. We also show that the local quench induces a deterministic orthogonality catastrophe for highly excited eigenstates, where the typical wave-function overlap between the pre- and postquench eigenstates decays exponentially with the system size.
High performance computing for classic gravitational N-body systems
Capuzzo-Dolcetta, Roberto
2009-01-01
The role of gravity is crucial in astrophysics. It determines the evolution of any system, over an enormous range of time and space scales. Astronomical stellar systems as composed by N interacting bodies represent examples of self-gravitating systems, usually treatable with the aid of newtonian gravity but for particular cases. In this note I will briefly discuss some of the open problems in the dynamical study of classic self-gravitating N-body systems, over the astronomical range of N. I will also point out how modern research in this field compulsorily requires a heavy use of large scale computations, due to the contemporary requirement of high precision and high computational speed.
Kolmogorov-Sinai entropy of many-body Hamiltonian systems.
Lakshminarayan, Arul; Tomsovic, Steven
2011-07-01
The Kolmogorov-Sinai (KS) entropy is a central measure of complexity and chaos. Its calculation for many-body systems is an interesting and important challenge. In this paper, the evaluation is formulated by considering N-dimensional symplectic maps and deriving a transfer matrix formalism for the stability problem. This approach makes explicit a duality relation that is exactly analogous to one found in a generalized Anderson tight-binding model and leads to a formally exact expression for the finite-time KS entropy. Within this formalism there is a hierarchy of approximations, the final one being a diagonal approximation that only makes use of instantaneous Hessians of the potential to find the KS entropy. By way of a nontrivial illustration, the KS entropy of N identically coupled kicked rotors (standard maps) is investigated. The validity of the various approximations with kicking strength, particle number, and time are elucidated. An analytic formula for the KS entropy within the diagonal approximation is derived and its range of validity is also explored.
Dynamics of systems of extended bodies in monad representation
Energy Technology Data Exchange (ETDEWEB)
Chechin, L.M.
1995-07-01
A universal form proposed earlier by the author for the equations of motion is used to find a monad representation of the equations of motion of a system of N extended bodies in general relativity theory. An explicit form of the equations of motion in a fixed chronometric reference system is presented. It is shown that it differs from the known coordinate motion equations obtained by the Fock method.
Body motion in a resistive medium: an exactly solvable model
Energy Technology Data Exchange (ETDEWEB)
Molina, M. I. [Universidad de chile, Santiago (Chile)
2001-04-01
We introduce and solve in closed form, using momentum and kinetic energy balance, a simplified microscopic model of a body propagating in a one dimensional resistive medium. For a whole family of collisions with varying degree of inelasticities, we find that the effective resistive force on the moving body is opposite to and proportional to the square of the body's velocity. [Spanish] Se plantea y resuelve en forma exacta, usando balance del momentum y energia cinetica, un modelo microscopico simplificado en un cuerpo propagandose en un medio resistivo unidimensional. Para toda una familia de colisiones con diferente grado de inelasticidad, encontramos que la fuerza efectiva sobre el cuerpo es opuesta y proporcional al cuadrado de la velocidad del cuerpo.
Point vortex model for asymmetric inviscid wakes past bluff bodies
Energy Technology Data Exchange (ETDEWEB)
Elcrat, A [Mathematics and Statistics Department, Wichita State University, 1845 Fairmount St, Wichita, KS 67260 (United States); Ferlauto, M; Zannetti, L, E-mail: luca.zannetti@polito.it [Department of Mechanical and Aerospace Engineering, Politecnico di Torino, corso Duca degli Abruzzi 24, I-10129 Turin (Italy)
2014-06-01
Wakes past bluff bodies are modeled by means of point vortices standing in equilibrium. The consistency of the adopted model is discussed with respect to the asymptotic model proposed by Batchelor. It is shown that, in general, when symmetry is broken, the wake configuration may be neither closed, as for the Batchelor model, nor open, as for the Kirchhoff model. The proposed model has three degrees of freedom, which reduce to one when the locations of separation are prescribed. A further condition has been established for the closure of the wake which reduces the degrees of freedom to zero as for the asymptotic Batchelor model. The existence of multiple solutions, suggestive for real world phenomena, is discussed. (papers)
Design of a Dual-Band On-Body Antenna for a Wireless Body Area Network Repeater System
Directory of Open Access Journals (Sweden)
Kyeol Kwon
2012-01-01
Full Text Available A dual-band on-body antenna for a wireless body area network repeater system is proposed. The designed dual-band antenna has the maximum radiation directed toward the inside of the human body in the medical implantable communication service (MICS band in order to collect vital information from the human body and directed toward the outside in the industrial, scientific, and medical (ISM band to transmit that information to a monitoring system. In addition, the return loss property of the antenna is insensitive to human body effects by utilizing the epsilon negative zeroth-order resonance property.
Application of Three-dimensional Body Measurement System
Institute of Scientific and Technical Information of China (English)
无
2005-01-01
The configuration principles and functions of the non-contact three-dimensional (3D) body measurement system (BMS)developed by the Textile/Clothing Technology Corporation ([TC]2) are described in this paper. The advantages of this new system, compared with traditional contact body measurement instruments ( Martin instruments ) are discussed by selecting 40 female undergraduates of Donghua University as the scan objects. In the experiments both the Martin instruments and [TC]2 BMS were used respectively. According to the data of different position ( Bust Circumference, Full Waist, Full Hips, Bust Height, Front Waist Height and Back Waist Height) obtained from both of the methods we can get the correlation coefficient which is close to 1, indicating that the results of both methods have comparability. Finally some suggestions for the further applications of the non-contact BMS in the apparel development of China are given. Ke ywords : Body measurement, anth ro pormetr y , non- contact 3D body measurement system, apparel industry, made-tomeasure (MTM).
Exploring the human body space: A geographical information system based anatomical atlas
Directory of Open Access Journals (Sweden)
Antonio Barbeito
2016-06-01
Full Text Available Anatomical atlases allow mapping the anatomical structures of the human body. Early versions of these systems consisted of analogical representations with informative text and labeled images of the human body. With computer systems, digital versions emerged and the third and fourth dimensions were introduced. Consequently, these systems increased their efficiency, allowing more realistic visualizations with improved interactivity and functionality. The 4D atlases allow modeling changes over time on the structures represented. The anatomical atlases based on geographic information system (GIS environments allow the creation of platforms with a high degree of interactivity and new tools to explore and analyze the human body. In this study we expand the functions of a human body representation system by creating new vector data, topology, functions, and an improved user interface. The new prototype emulates a 3D GIS with a topological model of the human body, replicates the information provided by anatomical atlases, and provides a higher level of functionality and interactivity. At this stage, the developed system is intended to be used as an educational tool and integrates into the same interface the typical representations of surface and sectional atlases.
Configuration maintaining control of three-body ring tethered system based on thrust compensation
Huang, Panfeng; Liu, Binbin; Zhang, Fan
2016-06-01
Space multi-tethered systems have shown broad prospects in remote observation missions. This paper mainly focuses on the dynamics and configuration maintaining control of space spinning three-body ring tethered system for such mission. Firstly, we establish the spinning dynamic model of the three-body ring tethered system considering the elasticity of the tether using Newton-Euler method, and then validate the suitability of this model by numerical simulation. Subsequently, LP (Likins-Pringle) initial equilibrium conditions for the tethered system are derived based on rigid body's equilibrium theory. Simulation results show that tether slack, snapping and interaction between the tethers exist in the three-body ring system, and its' configuration can not be maintained without control. Finally, a control strategy based on thrust compensation, namely thrust to simulate tether compression under LP initial equilibrium conditions is designed to solve the configuration maintaining control problem. Control effects are verified by numerical simulation compared with uncontrolled situation. Simulation results show that the configuration of the three-body ring tethered system could maintain under this active control strategy.
Observation of entanglement propagation in a quantum many-body system
Jurcevic, P; Hauke, P; Hempel, C; Zoller, P; Blatt, R; Roos, C F
2014-01-01
The key to explaining a wide range of quantum phenomena is understanding how entanglement propagates around many-body systems. Furthermore, the controlled distribution of entanglement is of fundamental importance for quantum communication and computation. In many situations, quasiparticles are the carriers of information around a quantum system and are expected to distribute entanglement in a fashion determined by the system interactions. Here we report on the observation of magnon quasiparticle dynamics in a one-dimensional many-body quantum system of trapped ions representing an Ising spin model. Using the ability to tune the effective interaction range, and to prepare and measure the quantum state at the individual particle level, we observe new quasiparticle phenomena. For the first time, we reveal the entanglement distributed by quasiparticles around a many-body system. Second, for long-range interactions we observe the divergence of quasiparticle velocity and breakdown of the light-cone picture that is ...
Many-body methods in agent-based epidemic models
Nakamura, Gilberto M
2016-01-01
The susceptible-infected-susceptible (SIS) agent-based model is usually employed in the investigation of epidemics. The model describes a Markov process for a single communicable disease among susceptible (S) and infected (I) agents. However, the disease spreading forecasting is often restricted to numerical simulations, while analytic formulations lack both general results and perturbative approaches since they are subjected to asymmetric time generators. Here, we discuss perturbation theory, approximations and application of many-body techniques in epidemic models in the framework for squared norm of probability vector $|P(t)| ^2$, in which asymmetric time generators are replaced by their symmetric counterparts.
Whole-body acid-base modeling revisited
DEFF Research Database (Denmark)
Ring, Troels; Nielsen, Søren
2017-01-01
The textbook account of whole-body acid-base balance in terms of endogenous acid production, renal net acid excretion and gastrointestinal alkali absorption which is the only comprehensive model around, has never been applied in clinical practice or been formally validated. In order to improve...... understanding of acid-base modeling, we managed to write up this conventional model as an expression solely on urine chemistry. Renal net acid excretion and endogenous acid production was already formulated in terms of urine chemistry, and we could from the literature also see gastrointestinal alkali absorption...
Optimisation of the 3-body dynamics applied to extra-solar planetary systems
Windmiller, Gur; Orosz, Jerome
2007-01-01
The body of work presented here revolves around the investigation of the existence and nature of extra-solar planetary systems. The fitting of stellar radial velocity time series data is attempted by constructing a model to quantify the orbital properties of a star-planetary system. This is achieved with the Planetary Orbit Fitting Process (POFP). Though specific to the investigated problem, the POFP is founded on two separate, more general ideas. One is a Solver producing the gravitational dynamics of a Three-Body system by integrating its Newtonian equations of motion. The other is an independent optimisation scheme. Both have been devised using MATLAB. Applying the optimisation to the Solver results in a realistic Three-Body dynamics that best describes the radial velocity data under the model-specific orbital-observational constraints. Combining these aspects also allows for the study of dynamical instability derived from interaction, which is reaffirmed as a necessary criterion for evaluating the fit. Th...
Institute of Scientific and Technical Information of China (English)
TANG Hua-ping; PENG Ya-qing
2005-01-01
A kind of active vibration control method was presented through optimal design of driving load of multi-body system with quick startup and brake. Dynamical equation of multi-body system with quick startup and brake was built, and mathematical model of representing vibration control was also set up according to the moving process from startup to brake. Then optimization vibration control model of system driving load was founded by applying theory of optimization control, which takes rigid body moving variable of braking moment as the known condition, and vibration control equation of multi-body system with quick startup and brake was converted into boundary value problem of differential equation. The transient control algorithm of vibration was put forward, which is the analysis basis for the further research. Theoretical analysis and calculation of numerical examples show that the optimal design method for the multi-body system driving load can decrease the vibration of system with duplication.
Wu, Dehua
2016-01-01
The spatial position and distribution of human body meridian are expressed limitedly in the decision support system (DSS) of acupuncture and moxibustion at present, which leads to the failure to give the effective quantitative analysis on the spatial range and the difficulty for the decision-maker to provide a realistic spatial decision environment. Focusing on the limit spatial expression in DSS of acupuncture and moxibustion, it was proposed that on the basis of the geographic information system, in association of DSS technology, the design idea was developed on the human body meridian spatial DSS. With the 4-layer service-oriented architecture adopted, the data center integrated development platform was taken as the system development environment. The hierarchical organization was done for the spatial data of human body meridian via the directory tree. The structured query language (SQL) server was used to achieve the unified management of spatial data and attribute data. The technologies of architecture, configuration and plug-in development model were integrated to achieve the data inquiry, buffer analysis and program evaluation of the human body meridian spatial DSS. The research results show that the human body meridian spatial DSS could reflect realistically the spatial characteristics of the spatial position and distribution of human body meridian and met the constantly changeable demand of users. It has the powerful spatial analysis function and assists with the scientific decision in clinical treatment and teaching of acupuncture and moxibustion. It is the new attempt to the informatization research of human body meridian.
Model-Driven Approach for Body Area Network Application Development.
Venčkauskas, Algimantas; Štuikys, Vytautas; Jusas, Nerijus; Burbaitė, Renata
2016-05-12
This paper introduces the sensor-networked IoT model as a prototype to support the design of Body Area Network (BAN) applications for healthcare. Using the model, we analyze the synergistic effect of the functional requirements (data collection from the human body and transferring it to the top level) and non-functional requirements (trade-offs between energy-security-environmental factors, treated as Quality-of-Service (QoS)). We use feature models to represent the requirements at the earliest stage for the analysis and describe a model-driven methodology to design the possible BAN applications. Firstly, we specify the requirements as the problem domain (PD) variability model for the BAN applications. Next, we introduce the generative technology (meta-programming as the solution domain (SD)) and the mapping procedure to map the PD feature-based variability model onto the SD feature model. Finally, we create an executable meta-specification that represents the BAN functionality to describe the variability of the problem domain though transformations. The meta-specification (along with the meta-language processor) is a software generator for multiple BAN-oriented applications. We validate the methodology with experiments and a case study to generate a family of programs for the BAN sensor controllers. This enables to obtain the adequate measure of QoS efficiently through the interactive adjustment of the meta-parameter values and re-generation process for the concrete BAN application.
Model-Driven Approach for Body Area Network Application Development
Directory of Open Access Journals (Sweden)
Algimantas Venčkauskas
2016-05-01
Full Text Available This paper introduces the sensor-networked IoT model as a prototype to support the design of Body Area Network (BAN applications for healthcare. Using the model, we analyze the synergistic effect of the functional requirements (data collection from the human body and transferring it to the top level and non-functional requirements (trade-offs between energy-security-environmental factors, treated as Quality-of-Service (QoS. We use feature models to represent the requirements at the earliest stage for the analysis and describe a model-driven methodology to design the possible BAN applications. Firstly, we specify the requirements as the problem domain (PD variability model for the BAN applications. Next, we introduce the generative technology (meta-programming as the solution domain (SD and the mapping procedure to map the PD feature-based variability model onto the SD feature model. Finally, we create an executable meta-specification that represents the BAN functionality to describe the variability of the problem domain though transformations. The meta-specification (along with the meta-language processor is a software generator for multiple BAN-oriented applications. We validate the methodology with experiments and a case study to generate a family of programs for the BAN sensor controllers. This enables to obtain the adequate measure of QoS efficiently through the interactive adjustment of the meta-parameter values and re-generation process for the concrete BAN application.
Construction of an exactly solvable model of the many-body problem
Zettili, Nouredine; Bouayad, Nouredine
1996-02-01
We propose here a new model for the many-body problem that can be solved exactly through the diagonalization of its Hamiltonian. This model, which is founded on a Lie algebra, serves as a useful tool for testing the accuracy of many-body approximation methods. The model consists of a one-dimensional system of two distinguishable sets of fermions interacting via a schematic two-body force. We construct this model's Hamiltonian by means of vector operators that are the generators of an SO(2, 1) group and which satisfy a Lie algebra. We incorporate into the Hamiltonian a symmetry that yields a constant of the motion which, in turn, renders the size of the Hamiltonian matrix finite. The diagonalization of this finitely dimensional matrix gives the exact values of the energy spectrum.
Cascaded Network Body Channel Model for Intrabody Communication.
Wang, Hao; Tang, Xian; Choy, Chiu Sing; Sobelman, Gerald E
2016-07-01
Intrabody communication has been of great research interest in recent years. This paper proposes a novel, compact but accurate body transmission channel model based on RC distribution networks and transmission line theory. The comparison between simulation and measurement results indicates that the proposed approach accurately models the body channel characteristics. In addition, the impedance-matching networks at the transmitter output and the receiver input further maximize the power transferred to the receiver, relax the receiver complexity, and increase the transmission performance. Based on the simulation results, the power gain can be increased by up to 16 dB after matching. A binary phase-shift keying modulation scheme is also used to evaluate the bit-error-rate improvement.
Institute of Scientific and Technical Information of China (English)
王建一; 郝慧
2011-01-01
In this paper, the methods of creating 3D human body and data access in 3D clothing fitting system are summarized. And then talk about the present limitations and future prospects: deeper integration with virtual reality technology, so that consumers are free to travel and exchange ideas. And in this way people can also feel the whole features of clothes through watching, touching and smelling and even all of humans' senses.%本文主要针对三维试衣系统中三维人体的创建以及三维人体数据的获取方式进行总结,进而得出目前三维试衣系统的局限与未来发展的展望:深度融合虚拟现实技术,让消费者可以自由游走与交流,从视觉、嗅觉、味觉等全方位感受服装的特性.
Geometric methods for nonlinear many-body quantum systems
Lewin, Mathieu
2010-01-01
Geometric techniques have played an important role in the seventies, for the study of the spectrum of many-body Schr\\"odinger operators. In this paper we provide a formalism which also allows to study nonlinear systems. We start by defining a weak topology on many-body states, which appropriately describes the physical behavior of the system in the case of lack of compactness, that is when some particles are lost at infinity. We provide several important properties of this topology and use them to provide a simple proof of the famous HVZ theorem in the repulsive case. In a second step we recall the method of geometric localization in Fock space as proposed by Derezi\\'nski and G\\'erard, and we relate this tool to our weak topology. We then provide several applications. We start by studying the so-called finite-rank approximation which consists in imposing that the many-body wavefunction can be expanded using finitely many one-body functions. We thereby emphasize geometric properties of Hartree-Fock states and ...
Close encounters of the third-body kind. [intruding bodies in binary star systems
Davies, M. B.; Benz, W.; Hills, J. G.
1994-01-01
We simulated encounters involving binaries of two eccentricities: e = 0 (i.e., circular binaries) and e = 0.5. In both cases the binary contained a point mass of 1.4 solar masses (i.e., a neutron star) and a 0.8 solar masses main-sequence star modeled as a polytrope. The semimajor axes of both binaries were set to 60 solar radii (0.28 AU). We considered intruders of three masses: 1.4 solar masses (a neutron star), 0.8 solar masses (a main-sequence star or a higher mass white dwarf), and 0.64 solar masses (a more typical mass white dwarf). Our strategy was to perform a large number (40,000) of encounters using a three-body code, then to rerun a small number of cases with a three-dimensional smoothed particle hydrodynamics (SPH) code to determine the importance of hydrodynamical effects. Using the results of the three-body runs, we computed the exchange across sections, sigma(sub ex). From the results of the SPH runs, we computed the cross sections for clean exchange, denoted by sigma(sub cx); the formation of a triple system, denoted by sigma(sub trp); and the formation of a merged binary with an object formed from the merger of two of the stars left in orbit around the third star, denoted by sigma(sub mb). For encounters between either binary and a 1.4 solar masses neutron star, sigma(sub cx) approx. 0.7 sigma(sub ex) and sigma(sub mb) + sigma(sub trp) approx. 0.3 sigma(sub ex). For encounters between either binary and the 0.8 solar masses main-sequence star, sigma(sub cx) approx. 0.50 sigma(sub ex) and sigma(sub mb) + sigma(sub trp) approx. 1.0 sigma(sub ex). If the main sequence star is replaced by a main-sequence star of the same mass, we have sigma(sub cx) approx. 0.5 sigma(sub ex) and sigma(sub mb) + sigma(sub trp) approx. 1.6 sigma(sub ex). Although the exchange cross section is a sensitive function of intruder mass, we see that the cross section to produce merged binaries is roughly independent of intruder mass. The merged binaries produced have semi
The centre of mass of a ‘flying’ body revealed by a computational model
Simeão Carvalho, Paulo; José Rodrigues, Marcelo
2017-01-01
The interpretation of complex trajectories of rigid bodies by the identification of their centre of mass (CM), has a large potential for improving the understanding of the concept of CM at college and university level. Therefore, it is not surprising that there are several techniques described in the literature concerning how to identify the CM of rigid bodies. However, these techniques fail when the CM’s position in the body’s frame of reference changes when the body is at motion. In this work we present a computational model that allows the identification of the CM with very good accuracy, either when the CM’s position changes or is fixed in the body’s frame of reference. This model can be used for a system of bodies moving in a plane, for which the CM of each body coincides with its geometric centre. The effectiveness of this model is tested with experiments using video acquisition and numerical analysis, and can be done in experimental classes under controlled conditions. Students are then able to compare the computed CM with the experimental CM, and investigate why the bodies sometimes present weird trajectories. This property applies in particular to sports, so the model can be also very useful as an educational resource for the explanation of the motion of athletes, namely as a tool for optimizing their performance.
General theory of many body localized systems coupled to baths
Nandkishore, Rahul; Gopalakrishnan, Sarang
2016-01-01
We consider what happens when a many body localized system is coupled to a heat bath. Unlike previous works, we do not restrict ourselves to the limit where the bath is large and effectively Markovian, nor to the limit where back action on the bath is negligible. We identify limits where the effect of the bath can be captured by classical noise, and limits where it cannot. We also identify limits in which the bath delocalizes the system, as well as limits in which the system localizes the bat...
Engine Multi-Body with Flexible Crankshaft Modeling and Numerical Simulation
Institute of Scientific and Technical Information of China (English)
LIU Yong-hong; WANG Hong; GU Hong-liang; ZHANG You-yun
2005-01-01
A multi-body model of engine system with flexible crankshaft was presented in this paper to analyze the dynamic behavior of an internal combustion engine. The flexible crankshaft structural dynamics was coupled with the main bearing hydrodynamic lubrication in this model by a system approach. An application of an I4 engine was given to show this sophisticated simulation model and to predict the loads and the orbit plots in the journal bearings by the dynamic response of the multi-body engine system with flexible crankshaft. The numerical results show the capabilities and significance of the flexible crankshaft in this system. The objective of the research is to provide the scientific guidance for design and maintenance of the internal combustion engine.
On the construction of a new solvable model and validity of many-body approximation methods
Zettili, Nouredine; Villars, Felix M. H.
1987-07-01
This work deals both with the construction of a new analytically solvable model and with the quantitative test of the time-dependent Hartree-Fock (TDHF) method. First, we construct a new analytically solvable model, which serves as a testing ground for the various many-body approximation methods. The construction is based on two vector operators that are the generators of a Lie algebra. The model consists of a one-dimensional system of two distinguishable sets of fermions interacting via a schematic two-body force. The model has a simple analytic energy spectrum. Second, we use this model to test the validity of the TDHF approximation. Exact eigenvalues are compared with the corresponding solutions of the TDHF method. The TDHF approximation is shown to be reasonably accurate in the description of the system's eigenstates.
On the construction of a new solvable model and validity of many-body approximation methods
Energy Technology Data Exchange (ETDEWEB)
Zettili, N.; Villars, F.M.H.
1987-07-20
This work deals both with the construction of a new analytically solvable model and with the quantitative test of the time-dependent Hartree-Fock (TDHF) method. First, we construct a new analytically solvable model, which serves as a testing ground for the various many-body approximation methods. The construction is based on two vector operators that are the generators of a Lie algebra. The model consists of a one-dimensional system of two distinguishable sets of fermions interacting via a schematic two-body force. The model has a simple analytic energy spectrum. Second, we use this model to test the validity of the TDHF approximation. Exact eigenvalues are compared with the corresponding solutions of the TDHF method. The TDHF approximation is shown to be reasonably accurate in the description of the system's eigenstates.
Modelling soft tissue for kinematic analysis of multi-segment human body models.
Benham, M P; Wright, D K; Bibb, R
2001-01-01
Traditionally biomechanical models represent the musculoskeletal system by a series of rigid links connected by rigidly defined rotational joints. More recently though the mechanics of joints and the action of soft tissues has come under closer scrutiny: biomechanical models might now include a full range of physiological structures. However, soft tissue representation, within multi-segment human body models, presents significant problems; not least in computational speed. We present a method for representing soft tissue physiology which provides for soft tissue wrapping around multiple bony objects; while showing forces at the insertion points, as well as normal reactions due to contact between the soft and bony tissues. These soft tissue representations may therefore be used to constrain the joint, as ligaments would, or to generate motion, like a muscle, so that joints may be modelled which more accurately simulate musculoskeletal motion in all degrees of freedom--rotational and translational. This method produces soft tissues that do not need to be tied to a certain path or route between the bony structures, but may move with the motion of the model; demonstrating a more realistic analysis of soft tissue activity in the musculoskeletal system. The combination of solid geometry models of the skeletal structure, and these novel soft tissue representations, may also provide a useful approach to synthesised human motion.
Applying Twisted Boundary Conditions for Few-body Nuclear Systems
Körber, Christopher
2015-01-01
We describe and implement twisted boundary conditions for the deuteron and triton systems within finite-volumes using the nuclear lattice EFT formalism. We investigate the finite-volume dependence of these systems with different twists angles. We demonstrate how various finite-volume information can be used to improve calculations of binding energies in such a framework. Our results suggests that with appropriate twisting of boundaries, infinite-volume binding energies can be reliably extracted from calculations using modest volume sizes with cubic length $L\\approx8-14$ fm. Of particular importance is our derivation and numerical verification of three-body analogue of `i-periodic' twist angles that eliminate the leading order finite-volume effects to the three-body binding energy.
Universal three-body parameter in heteronuclear atomic systems
Wang, Yujun; D'Incao, J P; Greene, Chris H
2012-01-01
A three-body parameter (3BP) defines the energy spectrum of three particles when the Efimov effect arises. Until recently, it had been widely agreed that this parameter should not be universal. Our present study further predicts a universal 3BP for heteronuclear atomic systems near broad Feshbach resonances. In particular, we show for a system of one light and two heavy atoms a universal 3BP is expected even without an effective three-body short-range repulsion. This universality is explained by the universal properties of the van der Waals interactions in a simple Born-Oppenheimer (BO) picture. Finally, we show the numerically determined 3BPs for some combination of alkali atoms used in ultracold experiments.
Validation of body composition models for high school wrestlers.
Williford, H N; Smith, J F; Mansfield, E R; Conerly, M D; Bishop, P A
1986-04-01
This study investigates the utility of two equations for predicting minimum wrestling weight and three equations for predicting body density for the population of high school wrestlers. A sample of 54 wrestlers was assessed for body density by underwater weighing, residual volume by helium dilution, and selected anthropometric measures. The differences between observed and predicted responses were analyzed for the five models. Four statistical tests were used to validate the equations, including tests for the mean of differences, proportion of positive differences, equality of standard errors from regression, and equivalence of regression coefficients between original and second sample data. The Michael and Katch equation and two Forsyth and Sinning equations (FS1 and FS21) for body density did not predict as well as expected. The Michael and Katch equation tends to overpredict body density while FS1 underpredicts. The FS2 equation, consisting of a constant adjustment to FS1, predicts well near the mean but not at the ends of the sample range. The two Tcheng and Tipton equations produce estimates which slightly but consistently overpredict minimum wrestling weight, the long form equation by 2.5 pounds and the short form by 3.8 pounds. As a result the proportion of positive differences is less than would be expected. But based on the tests for the standard errors and regression coefficients, the evidence does not uniformly reject these two equations.
Entanglement replication in driven dissipative many-body systems.
Zippilli, S; Paternostro, M; Adesso, G; Illuminati, F
2013-01-25
We study the dissipative dynamics of two independent arrays of many-body systems, locally driven by a common entangled field. We show that in the steady state the entanglement of the driving field is reproduced in an arbitrarily large series of inter-array entangled pairs over all distances. Local nonclassical driving thus realizes a scale-free entanglement replication and long-distance entanglement distribution mechanism that has immediate bearing on the implementation of quantum communication networks.
Regularities in Many-body Systems Interacting by a Two-body Random Ensemble
Zhao, Y M; Yoshinaga, N
2003-01-01
The even-even nuclei always have zero ground state angular momenta $I$ and positive parities $\\pi$. This feature was believed to be just a consequence of the attractive short-range interactions between nucleons. However, in the presence of two-body random interactions, the predominance of $I^{\\pi}=0^+$ ground states (0 g.s.) was found to be robust both for bosons and for an even number of fermions. For simple systems, such as $d$ bosons, $sp$ bosons, $sd$ bosons, and a few fermions in single-$j$ shells for small $j$, there are a few approaches to predict and/or explain the distribution of angular momentum $I$ ground state probabilities. An empirical recipe to predict the $I$ g.s. probabilities is available for general cases, but a more fundamental understanding of the robustness of 0 g.s. dominance is still out of reach. Other interesting results are also reviewed concerning other robust phenomena of many-body systems in the presence of random interactions, such as odd-even staggering of binding energies, gen...
Relativistic three-body quark model of light baryons based on hypercentral approach
Aslanzadeh, M.; Rajabi, A. A.
2015-05-01
In this paper, we have treated the light baryons as a relativistic three-body bound system. Inspired by lattice QCD calculations, we treated baryons as a spin-independent three-quark system within a relativistic three-quark model based on the three-particle Klein-Gordon equation. We presented the analytical solution of three-body Klein-Gordon equation with employing the constituent quark model based on a hypercentral approach through which two- and three-body forces are taken into account. Herewith the average energy values of the up, down and strange quarks containing multiplets are reproduced. To describe the hyperfine structure of the baryon, the splittings within the SU(6)-multiplets are produced by the generalized Gürsey Radicati mass formula. The considered SU(6)-invariant potential is popular "Coulomb-plus-linear" potential and the strange and non-strange baryons spectra are in general well reproduced.
Simulation model of pollution spreading in the water bodies affected by mining mill
Directory of Open Access Journals (Sweden)
Kalinkina Natalia Mikhailovna
2015-09-01
Full Text Available Water bodies of the northern Karelia are polluted by liquid wastes of Kostomukshsky iron ore-dressing mill. The main components of these wastes are potassium ions. The processes of the potassium spreading in lake-river system of the River Kenty were studied using simulation modeling. For water bodies, where chemical observations were not carried out, the reconstruction of data was realized. The parameters of the model (constants of potassium transfer for seven lakes were calculated. These constants reflect the hydrological regime of water bodies and characterize high-speed transfer of potassium in the upstream and downstream, and low transfer rate - in the middle stream. It is shown that the vast majority of potassium (70% is carried out of the system Kenty and enters the lake Srednee Kuito
Simple electrical model and initial experiments for intra-body communications.
Gao, Y M; Pun, S H; Du, M; Mak, P U; Vai, M I
2009-01-01
Intra-Body Communication(IBC) is a short range "wireless" communication technique appeared in recent years. This technique relies on the conductive property of human tissue to transmit the electric signal among human body. This is beneficial for devices networking and sensors among human body, and especially suitable for wearable sensors, telemedicine system and home health care system as in general the data rates of physiologic parameters are low. In this article, galvanic coupling type IBC application on human limb was investigated in both its mathematical model and related experiments. The experimental results showed that the proposed mathematical model was capable in describing the galvanic coupling type IBC under low frequency. Additionally, the calculated result and experimental result also indicated that the electric signal induced by the transmitters of IBC can penetrate deep into human muscle and thus, provide an evident that IBC is capable of acting as networking technique for implantable devices.
Misra, Gaurav; Izadi, Maziar; Sanyal, Amit; Scheeres, Daniel
2016-04-01
The effects of dynamical coupling between the rotational (attitude) and translational (orbital) motion of spacecraft near small Solar System bodies is investigated. This coupling arises due to the weak gravity of these bodies, as well as solar radiation pressure. The traditional approach assumes a point-mass spacecraft model to describe the translational motion of the spacecraft, while the attitude motion is considered to be completely decoupled from the translational motion. The model used here to describe the rigid-body spacecraft dynamics includes the non-uniform rotating gravity field of the small body up to second degree and order along with the attitude dependent terms, solar tide, and solar radiation pressure. This model shows that the second degree and order gravity terms due to the small body affect the dynamics of the spacecraft to the same extent as the orbit-attitude coupling due to the primary gravity (zeroth order) term. Variational integrators are used to simulate the dynamics of both the rigid spacecraft and the point mass. The small bodies considered here are modeled after Near-Earth Objects (NEO) 101955 Bennu, and 25143 Itokawa, and are assumed to be triaxial ellipsoids with uniform density. Differences in the numerically obtained trajectories of a rigid spacecraft and a point mass are then compared, to illustrate the impact of the orbit-attitude coupling on spacecraft dynamics in proximity of small bodies. Possible implications on the performance of model-based spacecraft control and on the station-keeping budget, if the orbit-attitude coupling is not accounted for in the model of the dynamics, are also discussed. An almost globally asymptotically stable motion estimation scheme based solely on visual/optical feedback that estimates the relative motion of the asteroid with respect to the spacecraft is also obtained. This estimation scheme does not require a model of the dynamics of the asteroid, which makes it perfectly suited for asteroids whose
Lattice location of dopant atoms: An -body model calculation
Indian Academy of Sciences (India)
N K Deepak
2010-03-01
The channelling and scattering yields of 1 MeV -particles in the $\\langle 1 0 0 \\rangle$, $\\langle 1 1 0 \\rangle and $\\langle 1 1 1 \\rangle$ directions of silicon implanted with bismuth and ytterbium have been simulated using -body model. The close encounter yield from dopant atoms in silicon is determined from the flux density, using the Bontemps and Fontenille method. All previous works reported in literature so far have been done with computer programmes using a statistical analytical expression or by a binary collision model or a continuum model. These results at the best gave only the transverse displacement of the lattice site from the concerned channelling direction. Here we applied the superior -body model to study the yield from bismuth in silicon. The finding that bismuth atom occupies a position close to the silicon substitutional site is new. The transverse displacement of the suggested lattice site from the channelling direction is consistent with the experimental results. The above model is also applied to determine the location of ytterbium in silicon. The present values show good agreement with the experimental results.
How do precision medicine and system biology response to human body's complex adaptability?
Yuan, Bing
2016-12-01
In the field of life sciences, although system biology and "precision medicine" introduce some complex scientifific methods and techniques, it is still based on the "analysis-reconstruction" of reductionist theory as a whole. Adaptability of complex system increase system behaviour uncertainty as well as the difficulties of precise identifification and control. It also put systems biology research into trouble. To grasp the behaviour and characteristics of organism fundamentally, systems biology has to abandon the "analysis-reconstruction" concept. In accordance with the guidelines of complexity science, systems biology should build organism model from holistic level, just like the Chinese medicine did in dealing with human body and disease. When we study the living body from the holistic level, we will fifind the adaptability of complex system is not the obstacle that increases the diffificulty of problem solving. It is the "exceptional", "right-hand man" that helping us to deal with the complexity of life more effectively.
A REVIEW ON LOWER APPENDICULAR MUSCULOSKELETAL SYSTEM OF HUMAN BODY
Directory of Open Access Journals (Sweden)
M. Akhtaruzzaman
2016-04-01
Full Text Available Rehabilitation engineering plays an important role in designing various autonomous robots to provide better therapeutic exercise to disabled patients. Hence it is necessary to study human musculoskeletal system and also needs to be presented in scientific manner in order to describe and analyze the biomechanics of human body motion. This review focuses on lower appendicular musculoskeletal structure of human body to represent joints and links architectures; to identify muscle attachments and functions; and to illustrate muscle groups which are responsible for a particular joint movement. Firstly, human lower skeletal structure, linking systems, joint mechanisms, and their functions are described with a conceptual representation of joint architecture of human skeleton. This section also represents joints and limbs by comparing with mechanical systems. Characteristics of ligaments and their functions to construct skeletal joints are also discussed briefly in this part. Secondly, the study focuses on muscular system of human lower limbs where muscle structure, functions, roles in moving endoskeleton structure, and supporting mechanisms are presented ellaborately. Thirdly, muscle groups are tabulated based on functions that provide mobility to different joints of lower limbs. Finally, for a particular movement action of lower extremity, muscles are also grouped and tabulated to have a better understanding on functions of individual muscle. Basically the study presents an overview of the structure of human lower limbs by characterizing and classifying skeletal and muscular systems.KEYWORDS: Musculoskeletal system; Human lower limbs; Muscle groups; Joint motion; Biomechatronics; Rehabilitation.
Dynamic propagation channel characterization and modeling for human body communication.
Nie, Zedong; Ma, Jingjing; Li, Zhicheng; Chen, Hong; Wang, Lei
2012-12-18
This paper presents the first characterization and modeling of dynamic propagation channels for human body communication (HBC). In-situ experiments were performed using customized transceivers in an anechoic chamber. Three HBC propagation channels, i.e., from right leg to left leg, from right hand to left hand and from right hand to left leg, were investigated under thirty-three motion scenarios. Snapshots of data (2,800,000) were acquired from five volunteers. Various path gains caused by different locations and movements were quantified and the statistical distributions were estimated. In general, for a given reference threshold è = -10 dB, the maximum average level crossing rate of the HBC was approximately 1.99 Hz, the maximum average fade time was 59.4 ms, and the percentage of bad channel duration time was less than 4.16%. The HBC exhibited a fade depth of -4 dB at 90% complementary cumulative probability. The statistical parameters were observed to be centered for each propagation channel. Subsequently a Fritchman model was implemented to estimate the burst characteristics of the on-body fading. It was concluded that the HBC is motion-insensitive, which is sufficient for reliable communication link during motions, and therefore it has great potential for body sensor/area networks.
Another New Solvable Many-Body Model of Goldfish Type
Directory of Open Access Journals (Sweden)
Francesco Calogero
2012-07-01
Full Text Available A new solvable many-body problem is identified. It is characterized by nonlinear Newtonian equations of motion (''acceleration equal force'' featuring one-body and two-body velocity-dependent forces ''of goldfish type'' which determine the motion ofan arbitrary number $N$ of unit-mass point-particles in a plane. The $N$ (generally complex values $z_{n}(t$ at time $t$ ofthe $N$ coordinates of these moving particles are given by the $N$eigenvalues of a time-dependent $Nimes N$ matrix $U(t$explicitly known in terms of the $2N$ initial data $z_{n}(0$and $dot{z}_{n}(0 $. This model comes in two dif/ferentvariants, one featuring 3 arbitrary coupling constants, the other only 2; for special values of these parameters all solutions are completely periodic with the same period independent of the initial data (''isochrony''; for other special values of these parameters this property holds up to corrections vanishing exponentially as $tightarrow infty$ (''asymptotic isochrony''. Other isochronous variants of these models are also reported. Alternative formulations, obtained by changing the dependent variables from the $N$ zeros of a monic polynomial of degree $N$ to its $N$ coefficients, are also exhibited. Some mathematical findings implied by some of these results - such as Diophantine properties of the zeros of certain polynomials - are outlined, but their analysis is postponed to a separate paper.
Dynamic Propagation Channel Characterization and Modeling for Human Body Communication
Directory of Open Access Journals (Sweden)
Lei Wang
2012-12-01
Full Text Available This paper presents the first characterization and modeling of dynamic propagation channels for human body communication (HBC. In-situ experiments were performed using customized transceivers in an anechoic chamber. Three HBC propagation channels, i.e., from right leg to left leg, from right hand to left hand and from right hand to left leg, were investigated under thirty-three motion scenarios. Snapshots of data (2,800,000 were acquired from five volunteers. Various path gains caused by different locations and movements were quantified and the statistical distributions were estimated. In general, for a given reference threshold è = −10 dB, the maximum average level crossing rate of the HBC was approximately 1.99 Hz, the maximum average fade time was 59.4 ms, and the percentage of bad channel duration time was less than 4.16%. The HBC exhibited a fade depth of −4 dB at 90% complementary cumulative probability. The statistical parameters were observed to be centered for each propagation channel. Subsequently a Fritchman model was implemented to estimate the burst characteristics of the on-body fading. It was concluded that the HBC is motion-insensitive, which is sufficient for reliable communication link during motions, and therefore it has great potential for body sensor/area networks.
Institute of Scientific and Technical Information of China (English)
周又和; 郑晓静
1999-01-01
The quantitative analysis shows that no theoretical model for 3-d magnetoelastic bodies, in literatures to date, can commonly simulate two kinds of distinct experimental phenomena on magnetoelastic interaction of ferromagnetic structures. This makes it difficult to effectively discribe the magnetoelastic mechanical behavior of structures with complex geometry, such as shells. Therefore, it is a key step for simulating magnetoelastic mechanical characteristics of structures with complex geometry to establish a 3-d model which also can commonly characterize the two distinct experimental phenomena. A theoretical model for three dimension magnetizable elastic bodies, which is commonly suitable for the two kinds of experimental phenomena on magnetoelastic interaction of ferromagnetic plates, is presented by the variational principle for the total energy functional of the coupling system of the 3-d ferromagnetic bodies. It is found that for the case of linear isotropic magnetic materials, the magnetic forces
Navarro-Barrientos, J-Emeterio; Rivera, Daniel E; Collins, Linda M
2011-01-12
We present a dynamical model incorporating both physiological and psychological factors that predicts changes in body mass and composition during the course of a behavioral intervention for weight loss. The model consists of a three-compartment energy balance integrated with a mechanistic psychological model inspired by the Theory of Planned Behavior (TPB). The latter describes how important variables in a behavioural intervention can influence healthy eating habits and increased physical activity over time. The novelty of the approach lies in representing the behavioural intervention as a dynamical system, and the integration of the psychological and energy balance models. Two simulation scenarios are presented that illustrate how the model can improve the understanding of how changes in intervention components and participant differences affect outcomes. Consequently, the model can be used to inform behavioural scientists in the design of optimised interventions for weight loss and body composition change.
Kraft, S.; Puel, G.; Aubry, D.; Funfschilling, C.
2016-12-01
For the calibration of multi-body models of railway vehicles, the identification of the model parameters from on-track measurement is required. This involves the solution of an inverse problem by minimising the misfit function which describes the distance between model and measurement using optimisation methods. The application of gradient-based optimisation methods is advantageous but necessitates an efficient approach for the computation of the gradients considering the large number of model parameters and the costly evaluation of the forward model. This work shows that the application of the adjoint state approach to the nonlinear vehicle-track multi-body system is suitable, reducing on the one hand the computational cost and increasing on the other hand the precision of the gradients. Gradients from the adjoint state method are computed for vehicle models and validated taking into account measurement noise.
Lower body lift with superficial fascial system suspension.
Lockwood, T
1993-11-01
Multiple body contour deformities of the trunk and thighs are commonly treated in separate stages to limit postoperative complications and disability. Recent advances in the surgical design of the medial thigh lift and the lateral thigh/buttock lift along with an understanding of the functional anatomy of the superficial fascial system have significantly improved results and decreased complications of trunk/thigh lifts. The enhanced safety of current trunk/thigh lifts has allowed new combinations to treat multiple body contour deformities in a single stage. Laxity of the entire lower trunk and thigh regions can be treated in one stage in selected patients. The lower body lift combines the transverse flank/thigh/buttock lift and the fascial anchoring medial thigh lift in one operation. In addition to the expected tightening of the flank, buttocks, and total thighs, this procedure results in a surprising degree of epigastric and hypogastric tightening of mild to moderate abdominal laxity without direct surgical undermining or umbilical transposition. Ten patients having the lower body lift alone or in combination with liposuction and other body contouring procedures were followed for 6 to 24 months. The primary indication for surgery is moderate to severe soft-tissue laxity of the lower trunk and thighs with minimal or mild residual fat deposits. Skin contour irregularities due to skin laxity (cellulite of laxity) or to postliposuction adhesions are frequently present and may be severe. Patients with significant fat deposits may be treated initially with liposuction 3 to 4 months earlier to become candidates for this procedure. Key technical elements of this procedure include (1) both supine and lateral decubitus positioning with the hip flexed and abducted to allow overcorrection, (2) appropriate direct surgical undermining through superficial fascial system zones of adherence in the superior thigh while avoiding the lymphatics of the femoral triangle, (3) more
Experimental quantum simulation of entanglement in many-body systems.
Zhang, Jingfu; Wei, Tzu-Chieh; Laflamme, Raymond
2011-07-01
We employ a nuclear magnetic resonance (NMR) quantum information processor to simulate the ground state of an XXZ spin chain and measure its NMR analog of entanglement, or pseudoentanglement. The observed pseudoentanglement for a small-size system already displays a singularity, a signature which is qualitatively similar to that in the thermodynamical limit across quantum phase transitions, including an infinite-order critical point. The experimental results illustrate a successful approach to investigate quantum correlations in many-body systems using quantum simulators.
Experimental Quantum Simulation of Entanglement in Many-body Systems
Zhang, Jingfu; Laflamme, Raymond
2011-01-01
We employ a nuclear magnetic resonance (NMR) quantum information processor to simulate the ground state of an XXZ spin chain and measure its NMR analog of entanglement, or pseudo-entanglement. The observed pseudo-entanglement for a small system size already displays singularity, a signature which is qualitatively similar to that in thermodynamical limit across quantum phase transitions, including an infinite-order critical point. The experimental results illustrate a successful approach to investigate quantum correlations in many-body systems using quantum simulators.
2011-06-01
Developing Systems Engineering Graduate Programs Aligned to the Body of Knowledge and Curriculum to Advance Systems Engineering (BKCASETM...Developing Systems Engineering Graduate Programs Aligned to the Body of Knowledge and Curriculum to Advance Systems Engineering (BKCASETM) Guidelines 5a
Modeling of Body Mass Index by Newton's Second Law
Canessa, E
2008-01-01
Since laws of physics exist in nature, their possible relationship to terrestial growth is introduced. By considering the human body as a dynamic system of variable mass (and volume), growing under a gravity field, it is shown how natural laws may influence the vertical growth of humans. This approach makes sense because the non-linear percentile curves of different aspects of human physical growth from childhood to adolescence can be described in relation to physics laws independently of gender and nationality. Analytical relations for the dependence of stature, measured mass (weight), growth velocity (and their mix as the body mass index) on age are deduced with a set of common statistical parameters which could relate environmental, genetics and metabolism and different aspects of physical growth on earth. A relationship to the monotone smoothing using functional data analysis to estimate growth curves and its derivatives is established. A preliminary discussion is also presented on horizontal growth in an...
Thin Thermoelectric Generator System for Body Energy Harvesting
Settaluri, Krishna T.; Lo, Hsinyi; Ram, Rajeev J.
2012-06-01
Wearable thermoelectric generators (TEGs) harvest thermal energy generated by the body to generate useful electricity. The performance of these systems is limited by (1) the small working temperature differential between the body and ambient, (2) the desire to use natural air convection cooling on the cold side of the generator, and (3) the requirement for thin, lightweight systems that are comfortable for long-term use. Our work has focused on the design of the heat transfer system as part of the overall thermoelectric (TE) system. In particular, the small heat transfer coefficient for natural air convection results in a module thermal impedance that is smaller than that of the heat sink. In this heat-sink-limited regime, the thermal resistance of the generator should be optimized to match that of the heat sink to achieve the best performance. In addition, we have designed flat (1 mm thickness) copper heat spreaders to realize performance surpassing splayed pin heat sinks. Two-dimensional (2-D) heat spreading exploits the large surface area available in a wristband and allows patterned copper to efficiently cool the TE. A direct current (DC)/DC converter is integrated on the wristband. The system generates up to 28.5 μW/cm2 before the converter and 8.6 μW/cm2 after the converter, with 30% efficiency. It generates output of 4.15 V with overall thickness under 5 mm.
The Moon: An Archive of Small Body Migration in the Solar System
Joy, Katherine H.; Crawford, Ian A.; Curran, Natalie M.; Zolensky, Michael; Fagan, Amy F.; Kring, David A.
2016-10-01
The Moon is an archive of impact cratering in the Solar System throughout the past 4.5 billion years. It preserves this record better than larger, more complex planets like the Earth, Mars and Venus, which have largely lost their ancient crusts through geological reprocessing and hydrospheric/atmospheric weathering. Identifying the parent bodies of impactors (i.e. asteroid bodies, comets from the Kuiper belt or the Oort Cloud) provides geochemical and chronological constraints for models of Solar System dynamics, helping to better inform our wider understanding of the evolution of the Solar System and the transfer of small bodies between planets. In this review article, we discuss the evidence for populations of impactors delivered to the Moon at different times in the past. We also propose approaches to the identification and characterisation of meteoritic material on the Moon in the context of future lunar exploration efforts.
The Moon: An Archive of Small Body Migration in the Solar System
Joy, Katherine H.; Crawford, Ian A.; Curran, Natalie M.; Zolensky, Michael; Fagan, Amy F.; Kring, David A.
2016-11-01
The Moon is an archive of impact cratering in the Solar System throughout the past 4.5 billion years. It preserves this record better than larger, more complex planets like the Earth, Mars and Venus, which have largely lost their ancient crusts through geological reprocessing and hydrospheric/atmospheric weathering. Identifying the parent bodies of impactors (i.e. asteroid bodies, comets from the Kuiper belt or the Oort Cloud) provides geochemical and chronological constraints for models of Solar System dynamics, helping to better inform our wider understanding of the evolution of the Solar System and the transfer of small bodies between planets. In this review article, we discuss the evidence for populations of impactors delivered to the Moon at different times in the past. We also propose approaches to the identification and characterisation of meteoritic material on the Moon in the context of future lunar exploration efforts.
Luzzati, Vittorio; Tardieu, Annette; Gulik-Krzywicki, Tadeusz
1981-01-01
The observed intensities of the reflections from the body-centered cubic phase of lipid systems are shown to be incompatible with a recently reported model consisting of straight, indefinitely long rods.
Current operators in relativistic few-body systems
Energy Technology Data Exchange (ETDEWEB)
Coester, F.; Klink, W.H.; Polyzou, W.N.
1995-08-01
The interpretation of experiments that explore hadron structure with electromagnetic probes requires both a nonperturbative representation of the hadron states and a compatible representation of the current-density operator. Intuitive interpretations depend strongly on the {open_quotes}impulse approximation{close_quotes}, that is, the use of one-body currents. One-body currents, however, cannot satisfy essentially the constraints imposed by the dynamics. In nonrelativistic quantum mechanics the problem of constructing dynamically required interaction currents is well understood and has been solved. Since Galilei transformations are kinematic, only time-translation covariance and current conservation impose dynamical constraints on current operators. These constraints can be satisfied by the well-known construction of so-called {open_quotes}minimal{close_quotes} or {open_quotes}model-independent{close_quotes} currents. Descriptions of hadron structure and of nuclear effects probed at high energies require a relativistic description. In relativistic few-body dynamics, one-body currents are covariant only under the kinematic subgroup of the Poincare group. Full Poincare covariance and current conservation implies dynamically determined interaction currents. The separation of the current operator into impulse current and interaction current depends on the {open_quotes}form of dynamics{close_quotes}, that is on the choice of the kinematic subgroup. The choice of the light-front kinematics has unique advantages not available with other forms of dynamics: (1) a relevant subgroup of the translations is kinematic, (2) initial and final states are related by kinematic Lorentz transformations, (3) the contributions of the individual constituents are related kinematically to the total current. These features were exploited successfully in calculations of deuteron form factors and quark-model form factors of hadrons.
Systemic lupus erythematosus following total body irradiation for malignant lymphoma.
Spinozzi, F; Capodicasa, E; Gerli, R; Bertotto, A; Rambotti, P; Grignani, F
1986-01-01
A case of a 63-year old man, who developed systemic lupus erythematosus three years after an initial diagnosis of small-cleaved centrofollicular lymphoma is described. The diagnosis of SLE was made on the basis of the accepted "1982 revised criteria for the classification of SLE". The autoimmune disease arose after a cycle of total body irradiation, despite the treatment with combination chemotherapeutic doses such a CVP or COAP or Cyclophosphamide, Vincristine, VM-26 and Prednisone. Genetic, immunological and exogenous environmental factors may co-exist and might equally be implicated in the pathogenesis of SLE and malignant lymphoma. However, the onset of SLE after total body irradiation could have been caused by the inactivation of suppressor T lymphocytes, which are known to be sensitive to radiations in vitro.
Quasi-Many-Body Localization in Translation-Invariant Systems
Yao, N. Y.; Laumann, C. R.; Cirac, J. I.; Lukin, M. D.; Moore, J. E.
2016-12-01
We examine localization phenomena associated with generic, high entropy, states of a translation-invariant, one-dimensional spin ladder. At early times, we find slow growth of entanglement entropy consistent with the known phenomenology of many-body localization in disordered, interacting systems. At intermediate times, however, anomalous diffusion sets in, leading to full spin polarization decay on an exponentially activated time scale. We identify a single length scale which parametrically controls both the spin transport times and the apparent divergence of the susceptibility to spin glass ordering. Ultimately, at the latest times, the exponentially slow anomalous diffusion gives way to diffusive thermal behavior. We dub the intermediate dynamical behavior, which persists over many orders of magnitude in time, quasi-many-body localization.
Modelling Railway Interlocking Systems
DEFF Research Database (Denmark)
Lindegaard, Morten Peter; Viuf, P.; Haxthausen, Anne Elisabeth
2000-01-01
In this report we present a model of interlocking systems, and describe how the model may be validated by simulation. Station topologies are modelled by graphs in which the nodes denote track segments, and the edges denote connectivity for train traÆc. Points and signals are modelled by annotatio...
Model Study of Three-Body Forces in the Three-Body Bound State
Liu, H; Glöckle, W; Elster, Ch.
2003-01-01
The Faddeev equations for the three-body bound state with two- and three-body forces are solved directly as three-dimensional integral equation. The numerical feasibility and stability of the algorithm, which does not employ partial wave decomposition is demonstrated. The three-body binding energy and the full wave function are calculated with Malfliet-Tjon-type two-body potentials and scalar Fujita-Miyazawa type three-body forces. The influence of the strength and range of the three-body force on the wave function, single particle momentum distributions and the two-body correlation functions are studied in detail. The extreme case of pure three-body forces is investigated as well.
Faraday Waves in Cold-Atom Systems with Two- and Three-Body Interactions
Tomio, Lauro; Gammal, A.; Abdullaev, F. K.
2017-03-01
We report an investigation on Bose-Einstein condensates with two-body (cubic) and three-body (quintic) interactions in the corresponding nonlinear Schrödinger equation, considering s-wave two-body scattering length a_s periodically varying in time. For the quintic interacting term, the dependence on a_s was considered within two models, being quadratic or quartic. It was shown that parametric instabilities can lead to th e generation of Faraday wave resonances in this system, with wavelengths depending on the background scattering length, as well as on the corresponding modulation parameters. A few sample results are shown here for repulsive a_s, in case of quadratic and quartic three-body interactions. The effect of dissipation is also verified on the amplitude of the resonances. Analytical predictions for the resonance positions are confirmed by our numerical simulations.
An inviscid model of flow separation around blunt bodies
Khristov, C. I.; Todorov, M. D.
The theoretical model developed by Christov and Todorov (1984) to describe separation in inviscid flows around blunt bodies is extended and refined, with an emphasis on the numerical implementation of the model. The two-dimensional steady flow around an infinite cylinder of starlike cross section is analyzed in polar coordinates, assuming the flow to be symmetric with respect to a plane containing the central axis of the cylinder, and the stagnation zones are treated using parabolic coordinates. Consideration is given to the coordinate transformation and the difference schemes for the Laplace equation and the equation for stagnation-zone shape. Numerical results are presented graphically and briefly characterized. It is found that separation is essentially an inviscid phenomenon, but triggered by viscosity; except for the skin friction, the resistance can be accurately assessed using the inviscid model.
Effective-one-body modeling of precessing black hole binaries
Taracchini, Andrea; Babak, Stanislav; Buonanno, Alessandra
2016-03-01
Merging black hole binaries with generic spins that undergo precessional motion emit complicated gravitational-wave signals. We discuss how such waveforms can be accurately modeled within an effective-one-body approach by (i) exploiting the simplicity of the signals in a frame that corotates with the orbital plane of the binary and (ii) relying on an accurate model of nonprecessing black hole binaries. The model is validated by extensive comparisons to 70 numerical relativity simulations of precessing black hole binaries and can generate inspiral-merger-ringdown waveforms for mass ratios up to 100 and any spin configuration. This work is an essential tool for studying and characterizing candidate gravitational-wave events in science runs of advanced LIGO.
Safety of children in cars: A review of biomechanical aspects and human body models
Directory of Open Access Journals (Sweden)
Karin Brolin
2015-03-01
To study how children interact with restraints during on-road driving and during pre- and in-crash events, numerical child models implementing age-specific anthropometric features will be essential. The review of human whole body models covers multi body models (age 1.5 to 15 years and finite element models (ages 3, 6, and 10 years. All reviewed child models are developed for crash scenarios. The only finite element models to implement age dependent anthropometry details for the spine and pelvis were a 3 year-old model and an upcoming 10 year-old model. One ongoing project is implementing active muscles response in a 6 year-old multi body model to study pre-crash scenarios. These active models are suitable for the next important step in providing the automotive industry with adequate tools for development and assessment of future restraint systems in the full sequence of events from pre- to in-crash.
Quantum theory of many-body systems techniques and applications
Zagoskin, Alexandre
2014-01-01
This text presents a self-contained treatment of the physics of many-body systems from the point of view of condensed matter. The approach, quite traditionally, uses the mathematical formalism of quasiparticles and Green’s functions. In particular, it covers all the important diagram techniques for normal and superconducting systems, including the zero-temperature perturbation theory and the Matsubara, Keldysh and Nambu-Gor'kov formalism, as well as an introduction to Feynman path integrals. This new edition contains an introduction to the methods of theory of one-dimensional systems (bosonization and conformal field theory) and their applications to many-body problems. Intended for graduate students in physics and related fields, the aim is not to be exhaustive, but to present enough detail to enable the student to follow the current research literature, or to apply the techniques to new problems. Many of the examples are drawn from mesoscopic physics, which deals with systems small enough that quantum...
Berry, D.P.; Buckley, F.; Dillon, P.; Evans, R.D.; Rath, M.; Veerkamp, R.F.
2003-01-01
Genetic (co)variances between body condition score (BCS), body weight (BW), milk yield, and fertility were estimated using a random regression animal model extended to multivariate analysis. The data analyzed included 81,313 BCS observations, 91,937 BW observations, and 100,458 milk test-day yields
Many-body dispersion interactions from the exchange-hole dipole moment model.
Otero-de-la-Roza, A; Johnson, Erin R
2013-02-07
In this article, we present the extension of the exchange-hole dipole moment model (XDM) of dispersion interactions to the calculation of two-body and three-body dispersion energy terms to any order, 2(l)-pole oscillator strengths, and polarizabilities. By using the newly-formulated coefficients, we study the relative importance of the higher-order two-body and the leading non-additive three-body (triple-dipole) interactions in gas-phase as well as in condensed systems. We show that the two-body terms up to R(-10), but not the terms of higher-order, are essential in the correct description of the dispersion energy, while there are a number of difficulties related to the choice of the damping function, which precludes the use three-body triple-dipole contributions in XDM. We conclude that further study is required before the three-body term can be used in production XDM density-functional calculations and point out the salient problems regarding its use.
Aerodynamics on a transport aircraft type wing-body model
Schmitt, V.
1982-01-01
The DFLR-F4 wing-body combination is studied. The 1/38 model is formed by a 9.5 aspect ratio transonic wing and an Airbus A 310 fuselage. The F4 wing geometrical characteristics are described and the main experimental results obtained in the S2MA wind tunnel are discussed. Both wing-fuselage interferences and viscous effects, which are important on the wing due to a high rear loading, are investigated by performing 3D calculations. An attempt is made to find their limitations.
General coordinate invariance in quantum many-body systems
Brauner, Tomas; Monin, Alexander; Penco, Riccardo
2014-01-01
We extend the notion of general coordinate invariance to many-body, not necessarily relativistic, systems. As an application, we investigate nonrelativistic general covariance in Galilei-invariant systems. The peculiar transformation rules for the background metric and gauge fields, first introduced by Son and Wingate in 2005 and refined in subsequent works, follow naturally from our framework. Our approach makes it clear that Galilei or Poincare symmetry is by no means a necessary prerequisite for making the theory invariant under coordinate diffeomorphisms. General covariance merely expresses the freedom to choose spacetime coordinates at will, whereas the true, physical symmetries of the system can be separately implemented as "internal" symmetries within the vielbein formalism. A systematic way to implement such symmetries is provided by the coset construction. We illustrate this point by applying our formalism to nonrelativistic s-wave superfluids.
Body image altered by psoriasis. A study based on individual interviews and a model for body image
DEFF Research Database (Denmark)
Khoury, Lina R; Danielsen, Patricia L; Skiveren, Jette
2014-01-01
on patient body image were identified: body coverage, sexual inhibitions, the influence of social support, reduced exercise activity and a negative self-image. Furthermore, information obtained through the Dermatology Life Quality Index (DLQI) questionnaires did not entirely reflect statements from patients...... made during interviews. Conclusion: An altered body image has a psychosocial impact on patients with visible psoriasis that may result in increased body coverage, sexual inhibitions and reduced exercise activity. This further affects self-image negatively and influences how people with psoriasis handle......Background: Visible psoriasis skin symptoms have a severe psychological impact on quality of life. To improve clinical approaches, methods of assessing these aspects are needed. Objectives: To investigate the influence of psoriasis on patients' body image based on the Body Image Model (BIM...
An Evaluation of the Pea Pod System for Assessing Body Composition of Moderately Premature Infants.
Forsum, Elisabet; Olhager, Elisabeth; Törnqvist, Caroline
2016-04-22
(1) BACKGROUND: Assessing the quality of growth in premature infants is important in order to be able to provide them with optimal nutrition. The Pea Pod device, based on air displacement plethysmography, is able to assess body composition of infants. However, this method has not been sufficiently evaluated in premature infants; (2) METHODS: In 14 infants in an age range of 3-7 days, born after 32-35 completed weeks of gestation, body weight, body volume, fat-free mass density (predicted by the Pea Pod software), and total body water (isotope dilution) were assessed. Reference estimates of fat-free mass density and body composition were obtained using a three-component model; (3) RESULTS: Fat-free mass density values, predicted using Pea Pod, were biased but not significantly (p > 0.05) different from reference estimates. Body fat (%), assessed using Pea Pod, was not significantly different from reference estimates. The biological variability of fat-free mass density was 0.55% of the average value (1.0627 g/mL); (4) CONCLUSION: The results indicate that the Pea Pod system is accurate for groups of newborn, moderately premature infants. However, more studies where this system is used for premature infants are needed, and we provide suggestions regarding how to develop this area.
An Evaluation of the Pea Pod System for Assessing Body Composition of Moderately Premature Infants
Directory of Open Access Journals (Sweden)
Elisabet Forsum
2016-04-01
Full Text Available (1 Background: Assessing the quality of growth in premature infants is important in order to be able to provide them with optimal nutrition. The Pea Pod device, based on air displacement plethysmography, is able to assess body composition of infants. However, this method has not been sufficiently evaluated in premature infants; (2 Methods: In 14 infants in an age range of 3–7 days, born after 32–35 completed weeks of gestation, body weight, body volume, fat-free mass density (predicted by the Pea Pod software, and total body water (isotope dilution were assessed. Reference estimates of fat-free mass density and body composition were obtained using a three-component model; (3 Results: Fat-free mass density values, predicted using Pea Pod, were biased but not significantly (p > 0.05 different from reference estimates. Body fat (%, assessed using Pea Pod, was not significantly different from reference estimates. The biological variability of fat-free mass density was 0.55% of the average value (1.0627 g/mL; (4 Conclusion: The results indicate that the Pea Pod system is accurate for groups of newborn, moderately premature infants. However, more studies where this system is used for premature infants are needed, and we provide suggestions regarding how to develop this area.
Many-body Systems Interacting via a Two-body Random Ensemble average energy of each angular momentum
Zhao, Y M; Yoshinaga, N
2002-01-01
In this paper, we discuss the regularities of energy of each angular momentum $I$ averaged over all the states for a fixed angular momentum (denoted as $\\bar{E}_I$'s) in many-body systems interacting via a two-body random ensemble. It is found that $\\bar{E}_I$'s with $I \\sim I_{min}$ (minimum of $I$) or $I_{max}$ have large probabilities (denoted as ${\\cal P}(I)$) to be the lowest, and that ${\\cal P}(I)$ is close to zero elsewhere. A simple argument based on the randomness of the two-particle cfp's is given. A compact trajectory of the energy $\\bar{E}_I$ vs. $I(I+1)$ is found to be robust. Regular fluctuations of the $P(I)$ (the probability of finding $I$ to be the ground state) and ${\\cal P}(I)$ of even fermions in a single-$j$ shell and boson systems are found to be reverse, and argued by the dimension fluctuation of the model space. Other regularities, such as why there are 2 or 3 sizable ${\\cal P}(I)$'s with $I\\sim I_{min}$ and ${\\cal P}(I) \\ll {\\cal P}(I_{max})$'s with $I\\sim I_{max}$, why the coefficien...
Modeling a radiotherapy clinical procedure: total body irradiation.
Esteban, Ernesto P; García, Camille; De La Rosa, Verónica
2010-09-01
Leukemia, non-Hodgkin's lymphoma, and neuroblastoma patients prior to bone marrow transplants may be subject to a clinical radiotherapy procedure called total body irradiation (TBI). To mimic a TBI procedure, we modified the Jones model of bone marrow radiation cell kinetics by adding mutant and cancerous cell compartments. The modified Jones model is mathematically described by a set of n + 4 differential equations, where n is the number of mutations before a normal cell becomes a cancerous cell. Assuming a standard TBI radiotherapy treatment with a total dose of 1320 cGy fractionated over four days, two cases were considered. In the first, repopulation and sub-lethal repair in the different cell populations were not taken into account (model I). In this case, the proposed modified Jones model could be solved in a closed form. In the second, repopulation and sub-lethal repair were considered, and thus, we found that the modified Jones model could only be solved numerically (model II). After a numerical and graphical analysis, we concluded that the expected results of TBI treatment can be mimicked using model I. Model II can also be used, provided the cancer repopulation factor is less than the normal cell repopulation factor. However, model I has fewer free parameters compared to model II. In either case, our results are in agreement that the standard dose fractionated over four days, with two irradiations each day, provides the needed conditioning treatment prior to bone marrow transplant. Partial support for this research was supplied by the NIH-RISE program, the LSAMP-Puerto Rico program, and the University of Puerto Rico-Humacao.
Lifting Entry & Atmospheric Flight (LEAF) Applications at Solar System Bodies.
Lee, G.; Sen, B.; Polidan, R. S.
2015-12-01
Introduction: Northrop Grumman and L'Garde have continued the development of a hypersonic entry, maneuverable platform capable of performing long-duration (months to a year) in situ and remote measurements at any solar system body that possesses an atmosphere. The Lifting Entry & Atmospheric Flight (LEAF) family of vehicles achieve this capability by using a semi-buoyant, ultra-low ballistic coefficient vehicle whose lifting entry allows it to enter the atmosphere without an aeroshell. In this presentation, we discuss the application of the LEAF system at various solar system bodies: Venus, Titan, Mars, and Earth. We present the key differences in platform design as well as operational differences required by the various target environments. The Venus implementation includes propulsive capability to reach higher altitudes during the day and achieves full buoyancy in the "habitable layers" of Venus' atmosphere at night. Titan also offers an attractive operating environment, allowing LEAF designs that can target low, medium, or high altitude operations, also with propulsive capabilities to roam within each altitude regime. The Mars version is a glider that descends gradually, allowing targeted delivery of payloads to the surface. Finally, an Earth version could remain in orbit in a stowed state until activated, allowing rapid response type deployments to any region of the globe.
Scars of Invariant Manifolds in Interacting Few-Body Systems
Papenbrock, T; Weidenmüller, H A
1997-01-01
We present a novel extension of the concept of scars for the wave functions of classically chaotic few--body systems of identical particles with rotation and permutation symmetry. Generically there exist manifolds in classical phase space which are invariant under the action of a common subgroup of these two symmetries. Such manifolds are associated with highly symmetric configurations and, if sufficiently stable, support quantum resonances. Although not directly associated to individual periodic orbits, the resonances nevertheless cause scars which signify collective motion on the quantum level and which should be experimentally observable.
Robot and Human Surface Operations on Solar System Bodies
Weisbin, C. R.; Easter, R.; Rodriguez, G.
2001-01-01
This paper presents a comparison of robot and human surface operations on solar system bodies. The topics include: 1) Long Range Vision of Surface Scenarios; 2) Human and Robots Complement Each Other; 3) Respective Human and Robot Strengths; 4) Need More In-Depth Quantitative Analysis; 5) Projected Study Objectives; 6) Analysis Process Summary; 7) Mission Scenarios Decompose into Primitive Tasks; 7) Features of the Projected Analysis Approach; and 8) The "Getting There Effect" is a Major Consideration. This paper is in viewgraph form.
Boltzmann-Langevin one-body dynamics for fermionic systems
Directory of Open Access Journals (Sweden)
Napolitani P.
2012-07-01
Full Text Available A full implementation of the Boltzmann-Langevin equation for fermionic systems is introduced in a transport model for dissipative collisions among heavy nuclei. Fluctuations are injected in phase space and not, like in more conventional approaches, as a projection on suitable subspaces. The advantage of this model is to be specifically adapted to describe processes characterised by instabilities, like the formation of fragments from a hot nuclear system, and by dissipation, like the transparency in nucleus-nucleus collisions.
Local stress and heat flux in atomistic systems involving three-body forces.
Chen, Youping
2006-02-01
Local densities of fundamental physical quantities, including stress and heat flux fields, are formulated for atomistic systems involving three-body forces. The obtained formulas are calculable within an atomistic simulation, in consistent with the conservation equations of thermodynamics of continuum, and can be applied to systems with general two- and three-body interaction forces. It is hoped that this work may correct some misuse of inappropriate formulas of stress and heat flux in the literature, may clarify the definition of site energy of many-body potentials, and may serve as an analytical link between an atomistic model and a continuum theory. Physical meanings of the obtained formulas, their relation with virial theorem and heat theorem, and the applicability are discussed.
Body weight growth Model of Datong Yak in Qinghai
Institute of Scientific and Technical Information of China (English)
W.Minqiang; Zh.Huiling; L.Pingli; T.Yongqiang; L.Jiye; L.Zonglin
2005-01-01
Summary:This study was conducted to develop a suitable model for describing the growth pattern of the yak. The data used consisted of body weight records of 76 growing yak aged between 5 to 37 months. Three mathematical models were applied to describe the growth curves during this development period:①Y1=20.105 + 11. 250x-0. 526x2 ;used for describing the growth curve of yak aged 5 to 13 months;②Y2 = -359.687 + 49. 977x - 1. 249x2 ;used for animals aged 13 to 25 months;and ③Y3 = -833. 339 + 63. 772x - 1. 019x2 ;used for animals aged 25 to 37 months.
[An interactive three-dimensional model of the human body].
Liem, S L
2009-01-01
Driven by advanced computer technology, it is now possible to show the human anatomy on a computer. On the internet, the Visible Body programme makes it possible to navigate in all directions through the anatomical structures of the human body, using mouse and keyboard. Visible Body is a wonderful tool to give insight in the human structures, body functions and organs.
Review on modeling heat transfer and thermoregulatory responses in human body.
Fu, Ming; Weng, Wenguo; Chen, Weiwang; Luo, Na
2016-12-01
Several mathematical models of human thermoregulation have been developed, contributing to a deep understanding of thermal responses in different thermal conditions and applications. In these models, the human body is represented by two interacting systems of thermoregulation: the controlling active system and the controlled passive system. This paper reviews the recent research of human thermoregulation models. The accuracy and scope of the thermal models are improved, for the consideration of individual differences, integration to clothing models, exposure to cold and hot conditions, and the changes of physiological responses for the elders. The experimental validated methods for human subjects and manikin are compared. The coupled method is provided for the manikin, controlled by the thermal model as an active system. Computational Fluid Dynamics (CFD) is also used along with the manikin or/and the thermal model, to evaluate the thermal responses of human body in various applications, such as evaluation of thermal comfort to increase the energy efficiency, prediction of tolerance limits and thermal acceptability exposed to hostile environments, indoor air quality assessment in the car and aerospace industry, and design protective equipment to improve function of the human activities.
Classical simulation of quantum many-body systems
Huang, Yichen
Classical simulation of quantum many-body systems is in general a challenging problem for the simple reason that the dimension of the Hilbert space grows exponentially with the system size. In particular, merely encoding a generic quantum many-body state requires an exponential number of bits. However, condensed matter physicists are mostly interested in local Hamiltonians and especially their ground states, which are highly non-generic. Thus, we might hope that at least some physical systems allow efficient classical simulation. Starting with one-dimensional (1D) quantum systems (i.e., the simplest nontrivial case), the first basic question is: Which classes of states have efficient classical representations? It turns out that this question is quantitatively related to the amount of entanglement in the state, for states with "little entanglement'' are well approximated by matrix product states (a data structure that can be manipulated efficiently on a classical computer). At a technical level, the mathematical notion for "little entanglement'' is area law, which has been proved for unique ground states in 1D gapped systems. We establish an area law for constant-fold degenerate ground states in 1D gapped systems and thus explain the effectiveness of matrix-product-state methods in (e.g.) symmetry breaking phases. This result might not be intuitively trivial as degenerate ground states in gapped systems can be long-range correlated. Suppose an efficient classical representation exists. How can one find it efficiently? The density matrix renormalization group is the leading numerical method for computing ground states in 1D quantum systems. However, it is a heuristic algorithm and the possibility that it may fail in some cases cannot be completely ruled out. Recently, a provably efficient variant of the density matrix renormalization group has been developed for frustration-free 1D gapped systems. We generalize this algorithm to all (i.e., possibly frustrated) 1D
Aoi, Shinya; Yamashita, Tsuyoshi; Tsuchiya, Kazuo
2011-06-01
We investigated the dynamics of quadrupedal locomotion by constructing a simple quadruped model that consists of a body mechanical model and an oscillator network model. The quadruped model has front and rear bodies connected by a waist joint with a torsional spring and damper system and four limbs controlled by command signals from the oscillator network model. The simulation results reveal that the quadruped model produces various gait patterns through dynamic interactions among the body mechanical system, the oscillator network system, and the environment. They also show that it undergoes a gait transition induced by changes in the waist joint stiffness and the walking speed. In addition, the gait pattern transition exhibits a hysteresis similar to that observed in human and animal locomotion. We examined the hysteresis mechanism from a dynamic viewpoint.
Institute of Scientific and Technical Information of China (English)
徐利平; 邹奉元; 曹建达; 刘焘
2015-01-01
The clothing ift is an important factor affecting the quality of the garment appearance.Through experiments selected 157 young women in Jiangsu and Zhejiang as samples obtained using the three-dimensional body scanning system corresponding eigenvalues,use SPSS software to these parts of the correlation analysis and multiple regression analysis to the characteristic model of human conduct WHR site the study.The results showed that:WHR correlation bust signiifcantly; waist square section round and bust, waist circumference correlated signiifcantly; waist-sectional circumference below the bust, waist, hip signiifcant correlation; get waist-sectional circumference degree and bust, waist, hip, waist distance relationship from the equation, the establishment of Jiangsu and Zhejiang young female WHR site features model, in order to simplify data download waistline and improve the accuracy of the data obtained to make a contribution.%服装的合体性是影响服装外观质量的重要因素。文章通过实验选取了157名江浙青年女性作为样本，使用三维扫描系统得到人体相应的特征值，利用SPSS软件对这些部位进行了相关性分析和多元回归分析，从而对人体腰臀部位的特征模型进行研究。结果表明：腰围与臀围、胸围的相关性显著；腰上方截面围度与胸围、腰围的相关性显著；腰下方截面围度与胸围、腰围、臀围的相关性显著；得到了腰部截面围度与胸围、腰围、臀围、距腰围距离的关系方程式，建立了江浙青年女性腰臀部位特征模型，为简化下装腰围数据获得和提高数据的精确度作出了贡献。
Performance Evaluation of Zigbee Transceiver for Wireless Body Sensor System
Directory of Open Access Journals (Sweden)
Ruchita Pandey
2014-06-01
Full Text Available A cost effective impedance measurement system and a low costtransceiver device has been presented for wireless body sensor systems.The proposed device has an analog front end to measure bioimpedance and ZigBee device which provides reliable wireless communication.Bioelectric Impedance measurement enables to characterize the state of tissues.Tetrapolar method is an advance method for measuring impedance since it is a very easy and simple method for practical implementation.The principle of modified tetrapolar method and its wireless transimission through zigbee has been investigated here.Different modulation technique has been applied and it has been found that MSK based transceiver is an efficient one since it has low bit error rate and it produce constant envelope carrier signals which have no amplitude and phase varations,hence it will be a more power saving technique.
Levy distribution in many-body quantum systems
Energy Technology Data Exchange (ETDEWEB)
Denisov, Sergey; Ponomarev, Alexey V.; Hanggi, Peter [Institute of Physics, University of Augsburg (Germany)
2010-07-01
Levy distribution is known to describe a whole range of complex phenomena: classical chaotic transport, processes of subrecoil laser cooling, fluctuations of stock market indices, time series of single molecule blinking events, bursting activity of small neuronal networks, to name a few. The appearance of Levy distribution in a system output is a strong indicator of a long-range correlation ''skeleton'' which conducts system intrinsic dynamics. Using two complimentary approaches, the canonical and the grand-canonical formalisms, we discovered that the momentum distribution of N strongly interacting (hard-core) bosons at finite temperatures confined on a one-dimensional optical lattice obeys the Levy distribution. The tunable Levy spline reproduces momentum distributions up to one recoil momentum. Our finding allows for calibration of complex quantum many-body states by using a unique scaling exponent.
Modelling and Feedback Control of Bistability in a Turbulent Bluff Body Wake
Brackston, Rowan; Wynn, Andrew; Garcia de La Cruz, Juan Marcos; Rigas, Georgios; Morrison, Jonathan
2016-11-01
The turbulent wake behind many three-dimensional bluff bodies exhibits a bistable behaviour, the properties of which has been the subject of significant recent interest. This feature of the wake is known to contribute to the pressure drag on the body and is relevant for geometries representative of many road vehicles. Furthermore, due to its high visibility from surface mounted pressure measurements, it is a feature that may be observed and controlled in real-time. In Brackston et al. we have recently demonstrated such a feedback control strategy that aims to suppress the bistable feature of the wake. Starting from a stochastic modelling approach, we identify a linearised model for this mode of the flow, obtaining parameters via a system identification. The identified model is then used to design the feedback controller, with the aim of restoring the flow to the unstable, symmetric state. The controller is implemented experimentally at Re 2 . 3 ×105 and is found to both suppress the bistability of the flow and reduce the drag on the body. Furthermore, the control system is found to have a positive energy balance, providing a key demonstration of efficient feedback control applied to a 3D bluff body wake at turbulent Reynolds numbers.
Antonov problem and quasi-equilibrium states in N-body system
Taruya, A; Taruya, Atsushi; Sakagami, Masa-aki
2005-01-01
In this paper, a quantitative characterization for the evolutionary sequence of stellar self-gravitating system is investigated, focusing on the pre-collapse stage of the long-term dynamical evolution. In particular, we consider the quasi-equilibrium behaviors of the N-body systems in the setup of the so-called Antonov problem, i.e., self-gravitating N-body system confined in an adiabatic wall and try to seek a possible connection with thermostatistics of self-gravitating systems. For this purpose, a series of long-term N-body simulations with various initial conditions are performed. We found that a quasi-equilibrium sequence away from the thermal equilibrium can be characterized by the one-parameter family of the stellar models. Especially, the stellar polytropic distribution satisfying the effective equation of state $P\\propto\\rho^{1+1/n}$ provides an excellent approximation to the evolutionary sequence of the N-body system. Based on the numerical results, we discuss a link between the quasi-equilibrium st...
Vibration energy absorption in the whole-body system of a tractor operator
Directory of Open Access Journals (Sweden)
Jan Szczepaniak
2014-06-01
Full Text Available Many people are exposed to whole-body vibration (WBV in their occupational lives, especially drivers of vehicles such as tractor and trucks. The main categories of effects from WBV are perception degraded comfort interference with activities-impaired health and occurrence of motion sickness. Absorbed power is defined as the power dissipated in a mechanical system as a result of an applied force. The vibration-induced injuries or disorders in a substructure of the human system are primarily associated with the vibration power absorption distributed in that substructure. The vibration power absorbed by the exposed body is a measure that combines both the vibration hazard and the biodynamic response of the body. The article presents measurement method for determining vibration power dissipated in the human whole body system called Vibration Energy Absorption (VEA. The vibration power is calculated from the real part of the force-velocity cross-spectrum. The absorbed power in the frequency domain can be obtained from the cross-spectrum of the force and velocity. In the context of the vibration energy transferred to a seated human body, the real component reflects the energy dissipated in the biological structure per unit of time, whereas the imaginary component reflects the energy stored/released by the system. The seated human is modeled as a series/parallel 4-DOF dynamic models. After introduction of the excitation, the response in particular segments of the model can be analyzed. As an example, the vibration power dissipated in an operator has been determined as a function of the agricultural combination operating speed 1.39 – 4.16 ms[sup] -1 [/sup].
SAPHIR: a physiome core model of body fluid homeostasis and blood pressure regulation.
Thomas, S Randall; Baconnier, Pierre; Fontecave, Julie; Françoise, Jean-Pierre; Guillaud, François; Hannaert, Patrick; Hernández, Alfredo; Le Rolle, Virginie; Mazière, Pierre; Tahi, Fariza; White, Ronald J
2008-09-13
We present the current state of the development of the SAPHIR project (a Systems Approach for PHysiological Integration of Renal, cardiac and respiratory function). The aim is to provide an open-source multi-resolution modelling environment that will permit, at a practical level, a plug-and-play construction of integrated systems models using lumped-parameter components at the organ/tissue level while also allowing focus on cellular- or molecular-level detailed sub-models embedded in the larger core model. Thus, an in silico exploration of gene-to-organ-to-organism scenarios will be possible, while keeping computation time manageable. As a first prototype implementation in this environment, we describe a core model of human physiology targeting the short- and long-term regulation of blood pressure, body fluids and homeostasis of the major solutes. In tandem with the development of the core models, the project involves database implementation and ontology development.
Development of a Model for Water and Heat Exchange Between the Atmosphere and a Water Body
Institute of Scientific and Technical Information of China (English)
SUN Shufen; YAN Jinfeng; XIA Nan; SUN Changhai
2007-01-01
A model for studying the heat and mass exchange between the atmosphere and a water body is developed,in which the phase change process of water freezing in winter and melting in summer and the function of the convective mixing process are taken into consideration. The model uses enthalpy rather than temperature as the predictive variable. It helps to set up governing equations more concisely, to deal with the phase change process more easily, and make the numerical scheme simpler. The model is verified by observed data from Lake Kinneret for a non-frozen lake in summer time, and Lake Lower Two Medicine for a frozen lake in winter time. Reasonably good agreements between the model simulations and observed data indicate that the model can serve as a component for a water body in a land surface model. In order to more efficiently apply the scheme in a climate system model, a sensitivity study of various division schemes with less layers in the vertical direction in the water body is conducted. The results of the study show that the division with around 10 vertical layers could produce a prediction accuracy that is comparable to the fine division with around 40 layers.
Three-body model for the two-neutron decay of $^{16}$Be
Lovell, A E; Thompson, I J
2016-01-01
While diproton decay was first theorized in 1960 and first measured in 2002, it was first observed only in 2012. The measurement of $^{14}$Be in coincidence with two neutrons suggests that $^{16}$Be does decay through the simultaneous emission of two strongly correlated neutrons. In this work, we construct a full three-body model of $^{16}$Be (as $^{14}$Be + n + n) in order to investigate its configuration in the continuum and in particular the structure of its ground state. In order to describe the three-body system, effective n-$^{14}$Be potentials were constructed, constrained by the experimental information on $^{15}$Be. The hyperspherical R-matrix method was used to solve the three-body scattering problem, and the resonance energy of $^{16}$Be was extracted from a phase shift analysis. In order to reproduce the experimental resonance energy of $^{16}$Be within this three-body model, a three-body interaction was needed. For extracting the width of the ground state of $^{16}$Be, we use the full width at ha...
Modeling of Generic Slung Load System
DEFF Research Database (Denmark)
Bisgaard, Morten; Bendtsen, Jan Dimon; la Cour-Harbo, Anders
2009-01-01
This paper presents the result of the modelling and verification of a generic slung load system using a small-scale helicopter. The model is intended for use in simulation, pilot training, estimation, and control. The model is derived using a redundant coordinate formulation based on Gauss......' Principle of Least Constraint using the Udwadia-Kalaba equation and can be used to model all body to body slung load suspension types. The model provides intuitive and easy-to-use means of modelling and simulating different slung load suspension types. It includes detection of, and response to, wire...... slackening and tightening as well as aerodynamic coupling between the helicopter and the load. Furthermore, it is shown how the model can be easily used for multi-lift systems either with multiple helicopters or multiple loads. A numerical stabilisation algorithm is introduced and finally the use...
Laurent, Sébastien; Pierce, Matthieu; Delehaye, Marion; Yefsah, Tarik; Chevy, Frédéric; Salomon, Christophe
2017-03-10
We study three-body recombination in an ultracold Bose-Fermi mixture. We first show theoretically that, for weak interspecies coupling, the loss rate is proportional to Tan's contact. Second, using a ^{7}Li/^{6}Li mixture we probe the recombination rate in both the thermal and dual superfluid regimes. We find excellent agreement with our model in the BEC-BCS crossover. At unitarity where the fermion-fermion scattering length diverges, we show that the loss rate is proportional to n_{f}^{4/3}, where n_{f} is the fermionic density. This unusual exponent signals nontrivial two-body correlations in the system. Our results demonstrate that few-body losses can be used as a quantitative probe of quantum correlations in many-body ensembles.
Exotic few-body systems with a heavy meson
Yamaguchi, Yasuhiro
2014-09-01
Hadron as an impurity bound in nuclei causes interesting phenomena which do not emerge in normal nuclei. These effects would give us the information not only on the internal structure of the nuclei, but also on the changing properties of the impurity in the nuclear medium. The hadron-nucleus systems have been studied in the light flavor sector, especially. However, a strong attraction between a heavy meson (Dbar and B) and a nucleon, provided by the one pion exchange potential (OPEP), was suggested recently. The OPEP is enhanced by the heavy quark spin symmetry which induces the mass degeneracy between the heavy pseudoscalar and vector mesons. The attraction motivates us to investigate the Dbar (B) nuclei having the exotic flavor structure. Hence, these bound states are stable against the strong decay. We discuss the possible existence of exotic few-body states realized as DbarNN and BNN. The OPEP between the Dbar (B) meson and the nucleon N is considered. By solving coupled channel equations for PNN and P* NN channels (P (P*) is the heavy pseudoscalar (vector) meson), we obtain new three-body bound states and resonances. In these states, the tensor force of the OPEP plays an important role to yield the attraction.
Gamma-ray Albedo of Small Solar System Bodies
Energy Technology Data Exchange (ETDEWEB)
Moskalenko, I.V.
2008-03-25
We calculate the {gamma}-ray albedo flux from cosmic-ray (CR) interactions with the solid rock and ice in Main Belt asteroids and Kuiper Belt objects (KBOs) using the Moon as a template. We show that the {gamma}-ray albedo for the Main Belt and KBOs strongly depends on the small-body mass spectrum of each system and may be detectable by the forthcoming Gamma Ray Large Area Space Telescope (GLAST). If detected, it can be used to derive the mass spectrum of small bodies in the Main Belt and Kuiper Belt and to probe the spectrum of CR nuclei at close-to-interstellar conditions. The orbits of the Main Belt asteroids and KBOs are distributed near the ecliptic, which passes through the Galactic center and high Galactic latitudes. Therefore, the {gamma}-ray emission by the Main Belt and Kuiper Belt has to be taken into account when analyzing weak {gamma}-ray sources close to the ecliptic. The asteroid albedo spectrum also exhibits a 511 keV line due to secondary positrons annihilating in the rock. This may be an important and previously unrecognized celestial foreground for the INTErnational Gamma-Ray Astrophysics Laboratory (INTEGRAL) observations of the Galactic 511 keV line emission including the direction of the Galactic center. For details of our calculations and references see [1].
Asano, Masanari; Khrennikov, Andrei; Ohya, Masanori; Tanaka, Yoshiharu; Yamato, Ichiro
2016-05-28
We compare the contextual probabilistic structures of the seminal two-slit experiment (quantum interference experiment), the system of three interacting bodies andEscherichia colilactose-glucose metabolism. We show that they have the same non-Kolmogorov probabilistic structure resulting from multi-contextuality. There are plenty of statistical data with non-Kolmogorov features; in particular, the probabilistic behaviour of neither quantum nor biological systems can be described classically. Biological systems (even cells and proteins) are macroscopic systems and one may try to present a more detailed model of interactions in such systems that lead to quantum-like probabilistic behaviour. The system of interactions between three bodies is one of the simplest metaphoric examples for such interactions. By proceeding further in this way (by playing withn-body systems) we shall be able to find metaphoric mechanical models for complex bio-interactions, e.g. signalling between cells, leading to non-Kolmogorov probabilistic data.
Critical quasienergy states in driven many-body systems
Bastidas Valencia, Victor Manuel; Engelhardt, Georg; Perez-Fernandez, Pedro; Vogl, Malte; Brandes, Tobias
2015-03-01
A quantum phase transition (QPT) is characterized by non-analyticities of ground-state properties at the critical points. Recently it has been shown that quantum criticality emerges also in excited states of the system, which is referred to as an excited-state quantum phase transition (ESQPT). This kind of quantum criticality is intimately related to a level clustering at critical energies, which results in a logarithmic singularity in the density of states. Most of the previous studies on quantum criticality in excited states have been focused on time independent systems. Here we study spectral singularities that appear in periodically-driven many-body systems and show how the external control allows one to engineer geometrical features of the quasienergy landscape. In particular, we study singularities in the quasienergy spectrum of a fully-connected network consisting of two-level systems with time-dependent interactions. We discuss the characteristic signatures of these singularities in observables like the magnetization, which should be measurable with current technology. The authors gratefully acknowledge financial support by the DFG via grants BRA 1528/7, BRA 1528/8, SFB 910 (V.M.B., T.B.), the Spanish Ministerio de Ciencia e Innovacion (Grants No. FIS2011-28738-C02-01) and Junta de Andalucia (Grants No. FQM160).
ON THE KINEMATIC GEOMETRY OF MANY BODY SYSTEMS
Institute of Scientific and Technical Information of China (English)
Wu-YIHSIANG
1999-01-01
In mechanics, both classical and quantum, one studies the profound interaction between two types of energy, namely, the kinetic energy and the potential energy. The former can be organized as the kinematic metric on the configuration space while the latter can be represented by a suitable potential function, such as the Newtonian potential in celestial mechanics and the Coulomb potential in quantum mechanics of atomic and molecular physics. In this paper, the author studies the kinematic geometry of n-body systems. The main results axe (i) the introduction of a canonical coordinate system which reveals the total amount of kinematic symmetry by an SO(З) × O(n - 1) action in such a canonieal coordinate representation; (ii) an in depth analysis of the above kinematic system both in the setting of classical invariant theory and by the technique of equivarjant Riemannian geometry; (iii) a remarkably simple formula for the potential function in such a canonical coordinate system which reveals the well-fitting between the kinematic symmetry and the potential energy.
78 FR 73696 - Extension of Expiration Date for Mental Disorders Body System Listings; Correction
2013-12-09
... ADMINISTRATION 20 CFR Part 404 RIN 0960-AH62 Extension of Expiration Date for Mental Disorders Body System... date of the Mental Disorders body system in the Listing of Impairments (listings) in our regulations... Mental Disorders body system in the Listing of Impairments (listings) in our regulations. In this...
Analysis and Modelling of Muscles Motion during Whole Body Vibration
Directory of Open Access Journals (Sweden)
La Gatta A
2010-01-01
Full Text Available The aim of the study is to characterize the local muscles motion in individuals undergoing whole body mechanical stimulation. In this study we aim also to evaluate how subject positioning modifies vibration dumping, altering local mechanical stimulus. Vibrations were delivered to subjects by the use of a vibrating platform, while stimulation frequency was increased linearly from 15 to 60 Hz. Two different subject postures were here analysed. Platform and muscles motion were monitored using tiny MEMS accelerometers; a contra lateral analysis was also presented. Muscle motion analysis revealed typical displacement trajectories: motion components were found not to be purely sinusoidal neither in phase to each other. Results also revealed a mechanical resonant-like behaviour at some muscles, similar to a second-order system response. Resonance frequencies and dumping factors depended on subject and his positioning. Proper mechanical stimulation can maximize muscle spindle solicitation, which may produce a more effective muscle activation.
General Relativistic Precession in Small Solar System Bodies
Sekhar, Aswin; Werner, Stephanie; Hoffmann, Volker; Asher, David; Vaubaillon, Jeremie; Hajdukova, Maria; Li, Gongjie
2016-10-01
Introduction: One of the greatest successes of the Einstein's General Theory of Relativity (GR) was the correct prediction of the precession of perihelion of Mercury. The closed form expression to compute this precession tells us that substantial GR precession would occur only if the bodies have a combination of both moderately small perihelion distance and semi-major axis. Minimum Orbit Intersection Distance (MOID) is a quantity which helps us to understand the closest proximity of two orbits in space. Hence evaluating MOID is crucial to understand close encounters and collision scenarios better. In this work, we look at the possible scenarios where a small GR precession in argument of pericentre (ω) can create substantial changes in MOID for small bodies ranging from meteoroids to comets and asteroids.Analytical Approach and Numerical Integrations: Previous works have looked into neat analytical techniques to understand different collision scenarios and we use those standard expressions to compute MOID analytically. We find the nature of this mathematical function is such that a relatively small GR precession can lead to drastic changes in MOID values depending on the initial value of ω. Numerical integrations were done with package MERCURY incorporating the GR code to test the same effects. Numerical approach showed the same interesting relationship (as shown by analytical theory) between values of ω and the peaks/dips in MOID values. Previous works have shown that GR precession suppresses Kozai oscillations and this aspect was verified using our integrations. There is an overall agreement between both analytical and numerical methods.Summary and Discussion: We find that GR precession could play an important role in the calculations pertaining to MOID and close encounter scenarios in the case of certain small solar system bodies (depending on their initial orbital elements). Previous works have looked into impact probabilities and collision scenarios on
A many-body potential approach to modelling the thermomechanical properties of actinide oxides.
Cooper, M W D; Rushton, M J D; Grimes, R W
2014-03-12
A many-body potential model for the description of actinide oxide systems, which is robust at high temperatures, is reported for the first time. The embedded atom method is used to describe many-body interactions ensuring good reproduction of a range of thermophysical properties (lattice parameter, bulk modulus, enthalpy and specific heat) between 300 and 3000 K for AmO2, CeO2, CmO2, NpO2, ThO2, PuO2 and UO2. Additionally, the model predicts a melting point for UO2 between 3000 and 3100 K, in close agreement with experiment. Oxygen-oxygen interactions are fixed across the actinide oxide series because it facilitates the modelling of oxide solid solutions. The new potential is also used to predict the energies of Schottky and Frenkel pair disorder processes.
Multiscale Cloud System Modeling
Tao, Wei-Kuo; Moncrieff, Mitchell W.
2009-01-01
The central theme of this paper is to describe how cloud system resolving models (CRMs) of grid spacing approximately 1 km have been applied to various important problems in atmospheric science across a wide range of spatial and temporal scales and how these applications relate to other modeling approaches. A long-standing problem concerns the representation of organized precipitating convective cloud systems in weather and climate models. Since CRMs resolve the mesoscale to large scales of motion (i.e., 10 km to global) they explicitly address the cloud system problem. By explicitly representing organized convection, CRMs bypass restrictive assumptions associated with convective parameterization such as the scale gap between cumulus and large-scale motion. Dynamical models provide insight into the physical mechanisms involved with scale interaction and convective organization. Multiscale CRMs simulate convective cloud systems in computational domains up to global and have been applied in place of contemporary convective parameterizations in global models. Multiscale CRMs pose a new challenge for model validation, which is met in an integrated approach involving CRMs, operational prediction systems, observational measurements, and dynamical models in a new international project: the Year of Tropical Convection, which has an emphasis on organized tropical convection and its global effects.
Dynamical Temperature of a One- Dimensional Many-Body Systerm in the Lennard-Jones Model
Institute of Scientific and Technical Information of China (English)
刘觉平; 袁保仑
2001-01-01
A new way to derive the formula of the dynamical temperature by using the invariance of the Liouville measure and the ergodicity hypothesis is presented, based on the invariance of the functional under the transformation of the measure. The obtained dynamical temperature is intrinsic to the underlying dynamics of the system. A molecular dynamical simulation of a one-dimensional many-body system in the Lennard-Jones model has been performed. The temperature calculated from the Hamiltonian for the stationary state of the system coincides with that determined with the thermodynamical method.
Evaluation of Human Body Tracking System for Gesture-based Programming of Industrial Robots
DEFF Research Database (Denmark)
Høilund, Carsten; Krüger, Volker; Moeslund, Thomas B.
2012-01-01
Is low-cost tracking precise enough for recognition of pointing actions? We investigate the quality of the human body tracking available with a Kinect camera by comparing it to a state-of-the-art motion capture system. The application is action recognition with parametric hidden Markov Models...... (PHMMs) for programming industrial robots. The data from the Kinect is overall more noisy and potentially requires calibration. In conclusion, though, we believe the quality will be sufficient for use with PHMMs....
Statistical theory of the many-body nuclear system
De Pace, A
2002-01-01
A recently proposed statistical theory of the mean fields associated with the ground and excited collective states of a generic many-body system is extended by increasing the dimensions of the P-space. In applying the new framework to nuclear matter, in addition to the mean field energies we obtain their fluctuations as well, together with the ones of the wavefunctions, in first order of the expansion in the complexity of the Q-space states. The physics described by the latter is assumed to be random. To extract numerical predictions out of our scheme we develop a schematic version of the approach, which, while much simplified, yields results of significance on the size of the error affecting the mean fields, on the magnitude of the residual effective interaction, on the ground state spectroscopic factor and on the mixing occurring between the vectors spanning the P-space.
Numerical modelling of a turbulent bluff-body flow with Reynolds stress turbulent models
Institute of Scientific and Technical Information of China (English)
LI Guoxiu; Dirk ROEKAERTS
2005-01-01
Numerical modelling of a turbulent bluff-body flow has been performed using differential Reynolds stress models (DRSMs). To clarify the applicability of the existing DRSMs in this complex flow, several typical DRSMs, including LRR-IP model, JM model, SSG model, as well as a modified LRR-IP model, have been validated and evaluated. The performance difference between various DRSMs is quite significant. Most of the above mentioned DRSMs cannot provide overall satisfactory predictions for this challenging test case. Motivated by the deficiency of the existing approaches, a new modification of LRR-IP model has been proposed. A very significant improvement of the prediction of flow field is obtained.
Mechanical Systems, Classical Models
Teodorescu, Petre P
2007-01-01
All phenomena in nature are characterized by motion; this is an essential property of matter, having infinitely many aspects. Motion can be mechanical, physical, chemical or biological, leading to various sciences of nature, mechanics being one of them. Mechanics deals with the objective laws of mechanical motion of bodies, the simplest form of motion. In the study of a science of nature mathematics plays an important role. Mechanics is the first science of nature which was expressed in terms of mathematics by considering various mathematical models, associated to phenomena of the surrounding nature. Thus, its development was influenced by the use of a strong mathematical tool; on the other hand, we must observe that mechanics also influenced the introduction and the development of many mathematical notions. In this respect, the guideline of the present book is precisely the mathematical model of mechanics. A special accent is put on the solving methodology as well as on the mathematical tools used; vectors, ...
Directory of Open Access Journals (Sweden)
Sorin Dan ŞANDOR
2003-01-01
Full Text Available System Dynamics was introduced by Jay W. Forrester in the 1960s. Since then the methodology was adopted in many areas of natural or social sciences. This article tries to present briefly how this methodology works, both as Systems Thinking and as Modelling with Vensim computer software.
Body-wide hierarchical fuzzy modeling, recognition, and delineation of anatomy in medical images.
Udupa, Jayaram K; Odhner, Dewey; Zhao, Liming; Tong, Yubing; Matsumoto, Monica M S; Ciesielski, Krzysztof C; Falcao, Alexandre X; Vaideeswaran, Pavithra; Ciesielski, Victoria; Saboury, Babak; Mohammadianrasanani, Syedmehrdad; Sin, Sanghun; Arens, Raanan; Torigian, Drew A
2014-07-01
To make Quantitative Radiology (QR) a reality in radiological practice, computerized body-wide Automatic Anatomy Recognition (AAR) becomes essential. With the goal of building a general AAR system that is not tied to any specific organ system, body region, or image modality, this paper presents an AAR methodology for localizing and delineating all major organs in different body regions based on fuzzy modeling ideas and a tight integration of fuzzy models with an Iterative Relative Fuzzy Connectedness (IRFC) delineation algorithm. The methodology consists of five main steps: (a) gathering image data for both building models and testing the AAR algorithms from patient image sets existing in our health system; (b) formulating precise definitions of each body region and organ and delineating them following these definitions; (c) building hierarchical fuzzy anatomy models of organs for each body region; (d) recognizing and locating organs in given images by employing the hierarchical models; and (e) delineating the organs following the hierarchy. In Step (c), we explicitly encode object size and positional relationships into the hierarchy and subsequently exploit this information in object recognition in Step (d) and delineation in Step (e). Modality-independent and dependent aspects are carefully separated in model encoding. At the model building stage, a learning process is carried out for rehearsing an optimal threshold-based object recognition method. The recognition process in Step (d) starts from large, well-defined objects and proceeds down the hierarchy in a global to local manner. A fuzzy model-based version of the IRFC algorithm is created by naturally integrating the fuzzy model constraints into the delineation algorithm. The AAR system is tested on three body regions - thorax (on CT), abdomen (on CT and MRI), and neck (on MRI and CT) - involving a total of over 35 organs and 130 data sets (the total used for model building and testing). The training and
Human Body Modeling and Posture Simulating Based on 3D Surface Scan Data
Institute of Scientific and Technical Information of China (English)
马永有; 张辉; 任少云; 蒋寿伟
2003-01-01
This paper presents a new approach for modeling the human body by considering the motion state and the shape of whole body. The body model consists of a skeleton kinematic model and a surface model. The former is used to determine the posture of the body,and the latter is used to generate the body shape according to the given posture. The body surface is reconstructed with multi-segment B-spline surfaces based on the 3D scan data from a real human body.Using only a few joints parameters and the original surface scan data, the various body postures and the shape can be generated easily. The model has a strong potential of being used for ergonomic design,garment design, virtual reality environment, as well as creating human animation, etc.
Simulating open quantum systems: from many-body interactions to stabilizer pumping
Mueller, M; Zhou, Y L; Roos, C F; Zoller, P
2011-01-01
In a recent experiment, Barreiro et al. demonstrated the fundamental building blocks of an open-system quantum simulator with trapped ions [Nature 470, 486 (2011)]. Using up to five ions, single- and multi-qubit entangling gate operations were combined with optical pumping in stroboscopic sequences. This enabled the implementation of both coherent many-body dynamics as well as dissipative processes by controlling the coupling of the system to an artificial, suitably tailored environment. This engineering was illustrated by the dissipative preparation of entangled two- and four-qubit states, the simulation of coherent four-body spin interactions and the quantum non-demolition measurement of a multi-qubit stabilizer operator. In the present paper, we present the theoretical framework of this gate-based ("digital") simulation approach for open-system dynamics with trapped ions. In addition, we discuss how within this simulation approach minimal instances of spin models of interest in the context of topological q...
Optimization of actuator/sensor position of multi-body system with quick startup and brake
Institute of Scientific and Technical Information of China (English)
无
2007-01-01
A new method was put forward to optimize the position of actuator/sensor of multi-body system with quick startup and brake. Dynamical equation was established for the system with intelligent structure of piezoelectric actuators. According to the property of the modes varying with time, the performance index function was developed based on the optimal configuration principle of energy maximal dissipation, and the relevant optimal model was obtained. According to its characteristic, a float-encoding genetic algorithm, which is efficient, simple and excellent for solving the global-optimal solution of this problem, was adopted. Taking the plane manipulator as an example, the result of numerical calculation shows that, after the actuator/sensor position being optimized,the vibration amplitude of the multi-body system is reduced by 35% compared with that without optimization.
Modelling the relationship between body fat and the BMI.
Mills, T C; Gallagher, D; Wang, J; Heshka, S
2007-01-01
OBJECTIVE: Given the increasing concerns about the levels of obesity being reached throughout the world, this paper analyses the relationship between the most common index of obesity, the BMI, and levels of body fat. RESEARCH METHODS AND PROCEDURES: The statistical relationship, in terms of functional form, between body fat and BMI is analysed using a large data set which can be categorized by race, sex and age. RESULTS: Irrespective of race, body fat and BMI are linearly related for males, with age entering logarithmically and with a positive effect on body fat. Caucasian males have higher body fat irrespective of age, but African American males' body fat increases with age faster than that of Asians and Hispanics. Age is not a significant predictor of body fat for females, where the relationship between body fat and BMI is nonlinear except for Asians. Caucasian females have higher predicted body fat than other races, except at low BMIs, where Asian females are predicted to have the highest body fat. DISCUSSION: Using BMIs to make predictions about body fat should be done with caution, as such predictions will depend upon race, sex and age and can be relatively imprecise. The results are of practical importance for informing the current debate on whether standard BMI cut-off values for overweight and obesity should apply to all sex and racial groups given that these BMI values are shown to correspond to different levels of adiposity in different groups.
Myths, symbols and legends of solar system bodies
Alexander, Rachel
2015-01-01
This book is an amateur astronomer’s guide to the mythology and symbolism associated with the celestial bodies in the Solar System, and even includes some of the legendary tales of people who had or have a connection with these objects. It explores different cultures (for example, the Greco-Roman and the Norse) and different times and how stories were used to explain the worlds they saw above them. You’d be amazed how much of our world today reflects the myths and stories of these cultures! Most amateur astronomers are familiar with the various Solar System objects, but they will be only peripherally aware of what ancient cultures thought of these other worlds. In fact, the mythology of the planets challenges many twenty-first century concepts and beliefs There are other books available on astromythology, but this one focuses mostly on our own Solar System, as opposed to the constellations and deep sky objects. Alexander offers a new angle on timeless subjects and is exciting, informative and dramatic...
Moving from basic toward systems pharmacodynamic models.
Jusko, William J
2013-09-01
Building upon many classical foundations of pharmacology, a diverse array of mechanistic pharmacokinetic-pharmacodynamic (PK/PD) models have emerged based on mechanisms of drug action and primary rate-limiting or turnover processes in physiology. An array of basic models can be extended to handle various complexities including tolerance and can readily be employed as building blocks in assembling enhanced PK/PD or small systems models. Our corticosteroid models demonstrate these concepts as well as elements of horizontal and vertical integration of molecular to whole-body processes. The potential advantages and challenges in moving PK/PD toward systems models are described.
Collective motion in quantum many-body systems
Energy Technology Data Exchange (ETDEWEB)
Haemmerling, Jens
2011-06-07
We study the emergence of collective dynamics in the integrable Hamiltonian system of two finite ensembles of coupled harmonic oscillators. After identification of a collective degree of freedom, the Hamiltonian is mapped onto a model of Caldeira-Leggett type, where the collective coordinate is coupled to an internal bath of phonons. In contrast to the usual Caldeira-Leggett model, the bath in the present case is part of the system. We derive an equation of motion for the collective coordinate which takes the form of a damped harmonic oscillator. We show that the distribution of quantum transition strengths induced by the collective mode is determined by its classical dynamics. This allows us to derive the spreading for the collective coordinate from first principles. After that we study the interplay between collective and incoherent single-particle motion in a model of two chains of particles whose interaction comprises a non-integrable part. In the perturbative regime, but for a general form of the interaction, we calculate the Fourier transform of the time correlation for the collective coordinate. We obtain the remarkable result that it always has a unique semi-classical interpretation. We show this by a proper renormalization procedure which also allows us to map the non-integrable system to the integrable model of Caldeira-Leggett-type considered previously in which the bath is part of the system.
Characterizing and quantifying frustration in quantum many-body systems.
Giampaolo, S M; Gualdi, G; Monras, A; Illuminati, F
2011-12-23
We present a general scheme for the study of frustration in quantum systems. We introduce a universal measure of frustration for arbitrary quantum systems and we relate it to a class of entanglement monotones via an exact inequality. If all the (pure) ground states of a given Hamiltonian saturate the inequality, then the system is said to be inequality saturating. We introduce sufficient conditions for a quantum spin system to be inequality saturating and confirm them with extensive numerical tests. These conditions provide a generalization to the quantum domain of the Toulouse criteria for classical frustration-free systems. The models satisfying these conditions can be reasonably identified as geometrically unfrustrated and subject to frustration of purely quantum origin. Our results therefore establish a unified framework for studying the intertwining of geometric and quantum contributions to frustration.
An interactive VR system based on full-body tracking and gesture recognition
Zeng, Xia; Sang, Xinzhu; Chen, Duo; Wang, Peng; Guo, Nan; Yan, Binbin; Wang, Kuiru
2016-10-01
Most current virtual reality (VR) interactions are realized with the hand-held input device which leads to a low degree of presence. There is other solutions using sensors like Leap Motion to recognize the gestures of users in order to interact in a more natural way, but the navigation in these systems is still a problem, because they fail to map the actual walking to virtual walking only with a partial body of the user represented in the synthetic environment. Therefore, we propose a system in which users can walk around in the virtual environment as a humanoid model, selecting menu items and manipulating with the virtual objects using natural hand gestures. With a Kinect depth camera, the system tracks the joints of the user, mapping them to a full virtual body which follows the move of the tracked user. The movements of the feet can be detected to determine whether the user is in walking state, so that the walking of model in the virtual world can be activated and stopped by means of animation control in Unity engine. This method frees the hands of users comparing to traditional navigation way using hand-held device. We use the point cloud data getting from Kinect depth camera to recognize the gestures of users, such as swiping, pressing and manipulating virtual objects. Combining the full body tracking and gestures recognition using Kinect, we achieve our interactive VR system in Unity engine with a high degree of presence.
Spectra for the A = 6 reactions calculated from a three-body resonance model
Directory of Open Access Journals (Sweden)
Paris Mark W.
2016-01-01
Full Text Available We develop a resonance model of the transition matrix for three-body breakup reactions of the A = 6 system and present calculations for the nucleon observed spectra, which are important for inertial confinement fusion and Big Bang nucleosynthesis (BBN. The model is motivated by the Faddeev approach where the form of the T matrix is written as a sum of the distinct Jacobi coordinate systems corresponding to particle configurations (α, n-n and (n; n-α to describe the final state. The structure in the spectra comes from the resonances of the two-body subsystems of the three-body final state, namely the singlet (T = 1 nucleon-nucleon (NN anti-bound resonance, and the Nα resonances designated the ground state (Jπ = 3−2${{{3^ - }} \\over 2}$ and first excited state (Jπ = 1−2${{{1^ - }} \\over 2}$ of the A = 5 systems 5He and 5Li. These resonances are described in terms of single-level, single-channel R-matrix parameters that are taken from analyses of NN and Nα scattering data. While the resonance parameters are approximately charge symmetric, external charge-dependent effects are included in the penetrabilities, shifts, and hard-sphere phases, and in the level energies to account for internal Coulomb differences. The shapes of the resonance contributions to the spectrum are fixed by other, two-body data and the only adjustable parameters in the model are the combinatorial amplitudes for the compound system. These are adjusted to reproduce the observed nucleon spectra from measurements at the Omega and NIF facilities. We perform a simultaneous, least-squares fit of the tt neutron spectra and the 3He3He proton spectra. Using these amplitudes we make a prediction of the α spectra for both reactions at low energies. Significant differences in the tt and 3He3He spectra are due to Coulomb effects.
Spectra for the A = 6 reactions calculated from a three-body resonance model
Paris, Mark W.; Hale, Gerald M.
2016-06-01
We develop a resonance model of the transition matrix for three-body breakup reactions of the A = 6 system and present calculations for the nucleon observed spectra, which are important for inertial confinement fusion and Big Bang nucleosynthesis (BBN). The model is motivated by the Faddeev approach where the form of the T matrix is written as a sum of the distinct Jacobi coordinate systems corresponding to particle configurations (α, n-n) and (n; n-α) to describe the final state. The structure in the spectra comes from the resonances of the two-body subsystems of the three-body final state, namely the singlet (T = 1) nucleon-nucleon (NN) anti-bound resonance, and the Nα resonances designated the ground state (Jπ = {{{3^ - }} over 2}) and first excited state (Jπ = {{{1^ - }} over 2}) of the A = 5 systems 5He and 5Li. These resonances are described in terms of single-level, single-channel R-matrix parameters that are taken from analyses of NN and Nα scattering data. While the resonance parameters are approximately charge symmetric, external charge-dependent effects are included in the penetrabilities, shifts, and hard-sphere phases, and in the level energies to account for internal Coulomb differences. The shapes of the resonance contributions to the spectrum are fixed by other, two-body data and the only adjustable parameters in the model are the combinatorial amplitudes for the compound system. These are adjusted to reproduce the observed nucleon spectra from measurements at the Omega and NIF facilities. We perform a simultaneous, least-squares fit of the tt neutron spectra and the 3He3He proton spectra. Using these amplitudes we make a prediction of the α spectra for both reactions at low energies. Significant differences in the tt and 3He3He spectra are due to Coulomb effects.
Albano, Raffaele; Sole, Aurelia; Mirauda, Domenica; Adamowski, Jan
2016-10-01
Large debris, including vehicles parked along floodplains, can cause severe damage and significant loss of life during urban area flash-floods. In this study, the authors validated and applied the Smoothed Particle Hydrodynamics (SPH) model, developed in Amicarelli et al. (2015), which reproduces in 3D the dynamics of rigid bodies driven by free surface flows, to the design of flood mitigation measures. To validate the model, the authors compared the model's predictions to the results of an experimental setup, involving a dam breach that strikes two fixed obstacles and three transportable floating bodies. Given the accuracy of the results, in terms of water depth over time and the time history of the bodies' movements, the SPH model explored in this study was used to analyse the mitigation efficiency of a proposed structural intervention - the use of small barriers (groynes) to prevent the transport of floating bodies. Different groynes configurations were examined to identify the most appropriate design and layout for urban area flash-flood damage mitigation. The authors found that groynes positioned upstream and downstream of each floating body can be effective as a risk mitigation measure for damage resulting from their movement.
Dynamical instability and statistical behaviour of N-body systems
Cipriani, Piero; Di Bari, Maria
1998-12-01
In this paper, we argue about a synthetic characterization of the qualitative properties of generic many-degrees-of-freedom (mdf) dynamical systems (DS's) by means of a geometric description of the dynamics [Geometro-Dynamical Approach (GDA)]. We exhaustively describe the mathematical framework needed to link geometry and dynamical (in)stability, discussing in particular which geometrical quantity is actually related to instability and why some others cannot give, in general, any indication of the occurrence of chaos. The relevance of the Schur theorem to select such Geometrodynamic Indicators (GDI) of instability is then emphasized, as its implications seem to have been underestimated in some of the previous works. We then compare the analytical and numerical results obtained by us and by Pettini and coworkers concerning the FPU chain, verifying a complete agreement between the outcomes of averaging the relevant GDI's over phase space (Casetti and Pettini, 1995) and our findings (Cipriani, 1993), obtained in a more conservative way, time-averaging along geodesics. Along with the check of the ergodic properties of GDI's, these results confirm that the mechanism responsible for chaos in realistic DS's largely depends on the fluctuations of curvatures rather than on their negative values, whose occurrence is very unlikely. On these grounds we emphasize the importance of the virialization process, which separates two different regimes of instability. This evolutionary path, predicted on the basis of analytical estimates, receives clear support from numerical simulations, which, at the same time, confirm also the features of the evolution of the GDI's along with their dependence on the number of degrees of freedom, N, and on the other relevant parameters of the system, pointing out the scarce relevance of negative curvature (for N ≫ 1) as a source of instability. The general arguments outlined above, are then concretely applied to two specific N-body problems
Partial Averaging and Resonance Trapping in a Restricted Three-Body System
Haghighipour, N
2002-01-01
Based on the value of the orbital eccentricity of a particle and also its proximity to the exact resonant orbit in a three-body system, the Pendulum Approximation (Dermott & Murray 1983) or the Second Fundamental Model of Resonance (Andoyer 1903; Henrard & Lemaitre 1983) are commonly used to study the motion of that particle near its resonance state. In this paper, we present the method of partial averaging as an analytical approach to study the dynamical evolution of a body near a resonance. To focus attention on the capabilities of this technique, a restricted, circular and planar three-body system is considered and the dynamics of its outer planet while captured in a resonance with the inner body is studied. It is shown that the first-order partially averaged system resembles a mathematical pendulum whose librational motion can be viewed as a geometrical interpretation of the resonance capture phenomenon. The driving force of this pendulum corresponds to the gravitational attraction of the inner bo...
Dlugach, Zh. M.; Mishchenko, M. I.
2013-01-01
The results of photometric and polarimetric observations carried out for some bright atmosphere-less bodies of the Solar system near the zero phase angle reveal the simultaneous existence of two spectacular optical phenomena, the so-called brightness and polarization opposition effects. In a number of studies, these phenomena were explained by the influence of coherent backscattering. However, in general, the interference concept of coherent backscattering can be used only in the case where the particles are in the far-field zones of each other, i.e., when the scattering medium is rather rarefied. Because of this, it is important to prove rigorously and to demonstrate that the coherent backscattering effect may also exist in densely packed scattering media like regolith surface layers of celestial bodies. From the results of the computer modeling performed with the use of numerically exact solutions of the macroscopic Maxwell equations for discrete random media with different packing densities of particles, we studied the origin and evolution of all the opposition phenomena predicted by the coherent backscattering theory for low-packing-density media. It has been shown that the predictions of this theory remain valid for rather high-packing densities of particles that are typical, in particular, of regolith surfaces of the Solar system bodies. The results allow us to conclude that both opposition effects observed simultaneously in some high-albedo atmosphereless bodies of the Solar system are caused precisely by coherent backscattering of solar light in the regolith layers composed of microscopic particles.
Directory of Open Access Journals (Sweden)
Yuhwai Tseng
Full Text Available Intra-body communication is a new wireless scheme for transmitting signals through the human body. Understanding the transmission characteristics of the human body is therefore becoming increasingly important. Electrostatic-coupling intra-body communication system in a ground-free situation that integrate electronic products that are discretely located on individuals, such as mobile phones, PDAs, wearable computers, and biomedical sensors, are of particular interest.The human body is modeled as a simplified Resistor-Capacitor network. A virtual ground between the transmitter and receiver in the system is represented by a resister-capacitor network. Value of its resistance and capacitance are determined from a system perspective. The system is characterized by using a mathematical unit step function in digital baseband transmission scheme with and without Manchester code. As a result, the signal-to-noise and to-intersymbol-interference ratios are improved by manipulating the load resistor. The data transmission rate of the system is optimized. A battery-powered transmitter and receiver are developed to validate the proposal.A ground-free system fade signal energy especially for a low-frequency signal limited system transmission rate. The system transmission rate is maximized by simply manipulating the load resistor. Experimental results demonstrate that for a load resistance of 10k-50k Ω, the high-pass 3 dB frequency of the band-pass channel is 400kHz-2MHz in the worst-case scenario. The system allows a Manchester-coded baseband signal to be transmitted at speeds of up to 20M bit per second with signal-to-noise and signal-to-intersymbol-interference ratio of more than 10 dB.The human body can function as a high speed transmission medium with a data transmission rate of 20Mbps in an electrostatic-coupling intra-body communication system. Therefore, a wideband signal can be transmitted directly through the human body with a good signal
Modeling Sustainable Food Systems
Allen, Thomas; Prosperi, Paolo
2016-05-01
The processes underlying environmental, economic, and social unsustainability derive in part from the food system. Building sustainable food systems has become a predominating endeavor aiming to redirect our food systems and policies towards better-adjusted goals and improved societal welfare. Food systems are complex social-ecological systems involving multiple interactions between human and natural components. Policy needs to encourage public perception of humanity and nature as interdependent and interacting. The systemic nature of these interdependencies and interactions calls for systems approaches and integrated assessment tools. Identifying and modeling the intrinsic properties of the food system that will ensure its essential outcomes are maintained or enhanced over time and across generations, will help organizations and governmental institutions to track progress towards sustainability, and set policies that encourage positive transformations. This paper proposes a conceptual model that articulates crucial vulnerability and resilience factors to global environmental and socio-economic changes, postulating specific food and nutrition security issues as priority outcomes of food systems. By acknowledging the systemic nature of sustainability, this approach allows consideration of causal factor dynamics. In a stepwise approach, a logical application is schematized for three Mediterranean countries, namely Spain, France, and Italy.
Moayyeri, Alireza; Hart, Deborah J; Snieder, Harold; Hammond, Christopher J; Spector, Timothy D; Steves, Claire J
2016-02-01
Little is known about the extent to which aging trajectories of different body systems share common sources of variance. We here present a large twin study investigating the trajectories of change in five systems: cardiovascular, respiratory, skeletal, morphometric, and metabolic. Longitudinal clinical data were collected on 3,508 female twins in the TwinsUK registry (complete pairs:740 monozygotic (MZ), 986 dizygotic (DZ), mean age at entry 48.9 ± 10.4, range 18-75 years; mean follow-up 10.2 ± 2.8 years, range 4-17.8 years). Panel data on multiple age-related variables were used to estimate biological ages for each individual at each time point, in linear mixed effects models. A weighted average approach was used to combine variables within predefined body system groups. Aging trajectories for each system in each individual were then constructed using linear modeling. Multivariate structural equation modeling of these aging trajectories showed low genetic effects (heritability), ranging from 2% in metabolic aging to 22% in cardiovascular aging. However, we found a significant effect of shared environmental factors on the variations in aging trajectories in cardiovascular (54%), skeletal (34%), morphometric (53%), and metabolic systems (53%). The remainder was due to environmental factors unique to each individual plus error. Multivariate Cholesky decomposition showed that among aging trajectories for various body systems there were significant and substantial correlations between the unique environmental latent factors as well as shared environmental factors. However, there was no evidence for a single common factor for aging. This study, the first of its kind in aging, suggests that diverse organ systems share non-genetic sources of variance for aging trajectories. Confirmatory studies are needed using population-based twin cohorts and alternative methods of handling missing data.
A Coupled Helicopter Rotor/Fuselage Dynamics Model Using Finite Element Multi-body
Directory of Open Access Journals (Sweden)
Cheng Qi-you
2016-01-01
Full Text Available To develop a coupled rotor/flexible fuselage model for vibration reduction studies, the equation of coupled rotor-fuselage is set up based on the theory of multi-body dynamics, and the dynamic analysis model is established with the software MSC.ADMAS and MSC.NASTRAN. The frequencies and vibration acceleration responses of the system are calculated with the model of coupled rotor-fuselage, and the results are compared with those of uncoupled modeling method. Analysis results showed that compared with uncoupled model, the dynamic characteristic obtained by the model of coupled rotor-fuselage are some different. The intrinsic frequency of rotor is increased with the increase of rotational velocities. The results also show that the flying speed has obvious influence on the vibration acceleration responses of the fuselage. The vibration acceleration response in the vertical direction is much higher at the low speed and high speed flight conditions.
Quantum effects in many-body gravitating systems
Golovko, V A
2015-01-01
A hierarchy of equations for equilibrium reduced density matrices obtained earlier is used to consider systems of spinless bosons bound by forces of gravity alone. The systems are assumed to be at absolute zero of temperature under conditions of Bose condensation. In this case, a peculiar interplay of quantum effects and of very weak gravitational interaction between microparticles occurs. As a result, there can form spatially-bounded equilibrium structures macroscopic in size, both immobile and rotating. The size of a structure is inversely related to the number of particles in the structure. When the number of particles is relatively small the size can be enormous, whereas if this numbder equals Avogadro's number the radius of the structure is about 30 cm in the case that the structure consists of hydrogen atoms. The rotating objects have the form of rings and exhibit superfluidity. An atmosphere that can be captured by tiny celestial bodies from the ambient medium is considered too. The thickness of the at...
Blood-Forsythe, Martin A; DiStasio, Robert A; Car, Roberto; Aspuru-Guzik, Alán
2015-01-01
Accurate treatment of the long-range electron correlation energy, including van der Waals (vdW) or dispersion interactions, is essential for describing the structure, dynamics, and function of a wide variety of systems. Among the most accurate models for including dispersion into density functional theory (DFT) is the range-separated many-body dispersion (MBD) method [A. Ambrossetti et al., J. Chem. Phys. 140, 18A508 (2014)], in which the correlation energy is modeled at short-range by a semi-local density functional and at long-range by a model system of coupled quantum harmonic oscillators. In this work, we develop analytical gradients of the MBD energy with respect to nuclear coordinates, including all implicit coordinate dependencies arising from the partitioning of the charge density into Hirshfeld effective volumes. To demonstrate the efficiency and accuracy of these MBD gradients for geometry optimizations of systems with intermolecular and intramolecular interactions, we optimized conformers of the be...
Institute of Scientific and Technical Information of China (English)
王毅; 宋卫东; 佟德飞
2014-01-01
固定鸭舵式二维弹道修正弹修正组件相对弹体具有不同的滚转角速度，传统6D弹道模型不能有效描述弹丸的运动特性和规律。针对该问题，在修正组件和弹体无气动耦合的假设下，研究了修正组件、弹体的运动与弹丸运动的关系，分析了弹丸飞行过程中两刚体间的相互作用，综合两刚体的运动学和动力学方程建立了7D弹道模型。针对某型尾翼稳定弹建立了仿真模型，并对不同面积、不同舵偏角、不同修正组件质量3种状态进行了仿真分析。仿真结果表明，该模型可有效描述弹丸在飞行过程中的运动状态，且能够反映弹丸的弹道特性和运动规律。该模型可用于该型弹丸的弹道解算，并为该类弹丸的研究提供依据。%The correction components of 2D trajectory correction projectile(TCP)with fixed-canard have different roll-angular velocities relative to the body,and 6D trajectory model can’t effectively describe the motion characteristics of the proj ectile.To solve this problem,the proj ectile was treated as two rigid bodies.Under the assumption that the front component and the aft component have no pneumatic coupling,new coordinate frames were built,and mathematical rela-tionship between the force of the fixed component and airflow by redefining attacking angle and side slip angle was described.The relations of the movement of proj ectile,the correction component and the body component were studied.The interactive force between two rigid bodies during flight was analyzed.The 7D ballistic model was built through integrating kinematic equations and dynamic equations.Aiming at one fin-stability shell,the simulation model was built,and the simulation was carried out.The results show that this model can describe the motion state in the flight and reflect the traj ectory characteristics.This model can be used for ballistic solution,and it provides reference for studying the proj
Boccara, Nino
2010-01-01
Modeling Complex Systems, 2nd Edition, explores the process of modeling complex systems, providing examples from such diverse fields as ecology, epidemiology, sociology, seismology, and economics. It illustrates how models of complex systems are built and provides indispensable mathematical tools for studying their dynamics. This vital introductory text is useful for advanced undergraduate students in various scientific disciplines, and serves as an important reference book for graduate students and young researchers. This enhanced second edition includes: . -recent research results and bibliographic references -extra footnotes which provide biographical information on cited scientists who have made significant contributions to the field -new and improved worked-out examples to aid a student’s comprehension of the content -exercises to challenge the reader and complement the material Nino Boccara is also the author of Essentials of Mathematica: With Applications to Mathematics and Physics (Springer, 2007).
Directory of Open Access Journals (Sweden)
Justyna Nowakowska
2014-08-01
Full Text Available The number of implanted medical devices is steadily increasing and has become an effective intervention improving life quality, but still carries the risk of infection. These infections are mainly caused by biofilm-forming staphylococci that are difficult to treat due to the decreased susceptibility to both antibiotics and host defense mechanisms. To understand the particular pathogenesis and treatment tolerance of implant-associated infection (IAI animal models that closely resemble human disease are needed. Applications of the tissue cage and catheter abscess foreign body infection models in the mouse will be discussed herein. Both models allow the investigation of biofilm and virulence of various bacterial species and a comprehensive insight into the host response at the same time. They have also been proven to serve as very suitable tools to study the anti-adhesive and anti-infective efficacy of different biomaterial coatings. The tissue cage model can additionally be used to determine pharmacokinetics, efficacy and cytotoxicity of antimicrobial compounds as the tissue cage fluid can be aspirated repeatedly without the need to sacrifice the animal. Moreover, with the advance in innovative imaging systems in rodents, these models may offer new diagnostic measures of infection. In summary, animal foreign body infection models are important tools in the development of new antimicrobials against IAI and can help to elucidate the complex interactions between bacteria, the host immune system, and prosthetic materials.
A paradigm for human body finite element model integration from a set of regional models.
Thompson, A B; Gayzik, F S; Moreno, D P; Rhyne, A C; Vavalle, N A; Stitzel, J D
2012-01-01
Computational modeling offers versatility, scalability, and cost advantages to researchers in the trauma and injury biomechanics communities. The Global Human Body Models Consortium (GHBMC) is a group of government, industry, and academic researchers developing human body models (HBMs) that aim to become the standard tool to meet this growing research need. The objective of this study is to present the methods used to develop the average seated male occupant model (M50, weight = 78 kg, height = 175 cm) from five separately validated body region models (BRMs). BRMs include the head, neck, thorax, abdomen, and a combined pelvis and lower extremity model. Modeling domains were split at the atlanto-occipital joint, C7-T1 boundary, diaphragm, abdominal cavity (peritoneum/retroperitoneum), and the acetabulum respectively. BRM meshes are based on a custom CAD model of the seated male built from a multi-modality imaging protocol of a volunteer subject found in literature.[1] Various meshing techniques were used to integrate the full body model (FBM) including 1-D beam and discrete element connections (e.g. ligamentous structures), 2D shell nodal connections (e.g. inferior vena cava to right atrium), 3D hexahedral nodal connections (e.g. soft tissue envelope connections between regions), and contact definitions varying from tied (muscle insertions) to sliding (liver and diaphragm contact). The model was developed in a general-purpose finite element code, LS-Dyna (LTSC, Livermore, CA) R4.2.1., and consists of 1.95 million elements and 1.3 million nodes. The element breakdown by type is 41% hexahedral, 33.7% tetrahedral, 19.5% quad shells and 5% tria shell. The integration methodology presented highlights the viability of using a collaborative development paradigm for the construction of HBMs, and will be used as template for expanding the suite of GHBMC models.
Distributed generation systems model
Energy Technology Data Exchange (ETDEWEB)
Barklund, C.R.
1994-12-31
A slide presentation is given on a distributed generation systems model developed at the Idaho National Engineering Laboratory, and its application to a situation within the Idaho Power Company`s service territory. The objectives of the work were to develop a screening model for distributed generation alternatives, to develop a better understanding of distributed generation as a utility resource, and to further INEL`s understanding of utility concerns in implementing technological change.
Energy Technology Data Exchange (ETDEWEB)
Ojima, D. [ed.
1992-12-31
The 1990 Global Change Institute (GCI) on Earth System Modeling is the third of a series organized by the Office for Interdisciplinary Earth Studies to look in depth at particular issues critical to developing a better understanding of the earth system. The 1990 GCI on Earth System Modeling was organized around three themes: defining critical gaps in the knowledge of the earth system, developing simplified working models, and validating comprehensive system models. This book is divided into three sections that reflect these themes. Each section begins with a set of background papers offering a brief tutorial on the subject, followed by working group reports developed during the institute. These reports summarize the joint ideas and recommendations of the participants and bring to bear the interdisciplinary perspective that imbued the institute. Since the conclusion of the 1990 Global Change Institute, research programs, nationally and internationally, have moved forward to implement a number of the recommendations made at the institute, and many of the participants have maintained collegial interactions to develop research projects addressing the needs identified during the two weeks in Snowmass.
You, Yi-Zhuang; Qi, Xiao-Liang; Xu, Cenke
We introduce the spectrum bifurcation renormalization group (SBRG) as a generalization of the real-space renormalization group for the many-body localized (MBL) system without truncating the Hilbert space. Starting from a disordered many-body Hamiltonian in the full MBL phase, the SBRG flows to the MBL fixed-point Hamiltonian, and generates the local conserved quantities and the matrix product state representations for all eigenstates. The method is applicable to both spin and fermion models with arbitrary interaction strength on any lattice in all dimensions, as long as the models are in the MBL phase. In particular, we focus on the 1 d interacting Majorana chain with strong disorder, and map out its phase diagram using the entanglement entropy. The SBRG flow also generates an entanglement holographic mapping, which duals the MBL state to a fragmented holographic space decorated with small blackholes.
Three-Body Model Analysis of Subbarrier alpha Transfer Reaction
Fukui, Tokuro; Yahiro, Masanobu
2011-01-01
Subbarrier alpha transfer reaction 13C(6Li,d)17O(6.356 MeV, 1/2+) at 3.6 MeV is analyzed with a alpha + d + 13C three-body model, and the asymptotic normalization coefficient (ANC) for alpha + 13C --> 17O(6.356 MeV, 1/2+), which essentially determines the reaction rate of 13C(alpha,n)16O, is extracted. Breakup effects of 6Li in the initial channel and those of 17O in the final channel are investigated with the continuum-discretized coupled-channels method (CDCC). The former is found to have a large back-coupling to the elastic channel, while the latter turns out significantly small. The transfer cross section calculated with Born approximation to the transition operator, including breakup states of 6Li, gives (C_{alpha 13C}{17O*})^2 =1.03 \\pm 0.29 fm^{-1}. This result is consistent with the value obtained by the previous DWBA calculation.
Energy Technology Data Exchange (ETDEWEB)
Neufeld, Esra; Gosselin, Marie-Christine; Murbach, Manuel; Christ, Andreas; Cabot, Eugenia; Kuster, Niels, E-mail: neufeld@itis.ethz.ch [Foundation for Research on Information Technologies in Society (IT' IS), Zeughausstr. 43, 8004 Zuerich (Switzerland)
2011-08-07
Multi-transmit coils are increasingly being employed in high-field magnetic resonance imaging, along with a growing interest in multi-transmit body coils. However, they can lead to an increase in whole-body and local specific absorption rate (SAR) compared to conventional body coils excited in circular polarization for the same total incident input power. In this study, the maximum increase of SAR for three significantly different human anatomies is investigated for a large 3 T (128 MHz) multi-transmit body coil using numerical simulations and a (generalized) eigenvalue-based approach. The results demonstrate that the increase of SAR strongly depends on the anatomy. For the three models and normalization to the sum of the rung currents squared, the whole-body averaged SAR increases by up to a factor of 1.6 compared to conventional excitation and the peak spatial SAR (averaged over any 10 cm{sup 3} of tissue) by up to 13.4. For some locations the local averaged SAR goes up as much as 800 times (130 when looking only at regions where it is above 1% of the peak spatial SAR). The ratio of the peak spatial SAR to the whole-body SAR increases by a factor of up to 47 and can reach values above 800. Due to the potentially much larger power deposition, additional, preferably patient-specific, considerations are necessary to avoid injuries by such systems.
Neufeld, Esra; Gosselin, Marie-Christine; Murbach, Manuel; Christ, Andreas; Cabot, Eugenia; Kuster, Niels
2011-08-01
Multi-transmit coils are increasingly being employed in high-field magnetic resonance imaging, along with a growing interest in multi-transmit body coils. However, they can lead to an increase in whole-body and local specific absorption rate (SAR) compared to conventional body coils excited in circular polarization for the same total incident input power. In this study, the maximum increase of SAR for three significantly different human anatomies is investigated for a large 3 T (128 MHz) multi-transmit body coil using numerical simulations and a (generalized) eigenvalue-based approach. The results demonstrate that the increase of SAR strongly depends on the anatomy. For the three models and normalization to the sum of the rung currents squared, the whole-body averaged SAR increases by up to a factor of 1.6 compared to conventional excitation and the peak spatial SAR (averaged over any 10 cm3 of tissue) by up to 13.4. For some locations the local averaged SAR goes up as much as 800 times (130 when looking only at regions where it is above 1% of the peak spatial SAR). The ratio of the peak spatial SAR to the whole-body SAR increases by a factor of up to 47 and can reach values above 800. Due to the potentially much larger power deposition, additional, preferably patient-specific, considerations are necessary to avoid injuries by such systems.
Metal-insulator transition in disordered systems from the one-body density matrix
DEFF Research Database (Denmark)
Olsen, Thomas; Resta, Raffaele; Souza, Ivo
2017-01-01
systems. In particular, for noninteracting systems the geometrical marker can be obtained from the configurational average of the norm-squared one-body density matrix, which can be calculated within open as well as periodic boundary conditions. This is in sharp contrast to a classification based...... on the static conductivity, which is only sensible within periodic boundary conditions. We exemplify the method by considering a simple lattice model, known to have a metal-insulator transition as a function of the disorder strength, and demonstrate that the transition point can be obtained accurately from...... the one-body density matrix. The approach has a general ab initio formulation and could in principle be applied to realistic disordered materials by standard electronic structure methods....
A New Application of Multi- Body System Dynamics in Vehicle- Road Interaction Simulation
Institute of Scientific and Technical Information of China (English)
Ren Wei-qun; Zhang Yun-qing; Jin Guo-dong
2003-01-01
In vehicle-road interaction simulation, multi-body system (MBS) dynamics as well as the corresponding software ADAMS has been employed to model the nonlinear vehicle in more detail. The simulation method has been vali-dated by the test data, and been compared to the former sim-ple models. This method can be used for estimating the effects of dynamic tire forces and other vehicle features on road damage so that the "road- friend liness" can be assessed in vehicle design process.
Human body composition models and methodology: theory and experiment.
Wang, Z.M.
1997-01-01
The study of human body composition is a branch of human biology which focuses on the in vivo quantification of body components, the quantitative relationships between components, and the quantitative changes in these components related to various influencing factors. Accordingly, the study of human
Three-body systems in physics of cold atoms and halo nuclei
Ji, Chen
2015-01-01
Few-body systems, such as cold atoms and halo nuclei, share universal features at low energies, which are insensitive to the underlying inter-particle interactions at short ranges. These low-energy properties can be investigated in the framework of effective field theory with two-body and three-body contact interactions. I review the effective-field-theory studies of universal physics in three-body systems, focusing on the application in cold atoms and halo nuclei.
A numerical study on detecting defects in a plane-stressed body by system identification
Energy Technology Data Exchange (ETDEWEB)
Shin, S. [Dong-A Univ., Pusan (Korea, Republic of) Dept. of Civil Eng.; Moo Koh, H. [Department of Civil Engineering, Seoul National University, Seoul (Korea, Republic of)
1999-06-01
A parametric system identification algorithm is applied for detecting holes or cracks in an elastic plane-stressed body using measured static response at the boundaries. A linearly constrained nonlinear optimization problem is solved for optimal constitutive parameters by minimizing the error between the measured and computed displacements. Each finite element in the model is parameterized by decomposing its stiffness matrix into constitutive parameters and kernel matrices. Because locations and sizes of actual holes or cracks in a body are not the a priori knowledge, the finite element model for detecting such defects is simply set up for the defect-free state with the assumption of a linear elastic behavior. Defects in a plane-stressed body are predicted by the reduction in the constitutive parameters of each element from their baseline values without modifying the geometry and topology of the defined finite element model. The proposed defect-detection algorithm allows sparse measured data with respect to the number of degrees of freedom of the model and also provides statistical defect indices when considering noise in measurements. An adaptive parameter grouping scheme is applied to localize defects when limited measurements are provided. The proposed method is investigated through numerically simulated examples. (orig.) 9 refs.
Gray Model of Body Figure%人体体型灰色模型建立
Institute of Scientific and Technical Information of China (English)
陈文飞; 潘箐
2000-01-01
Body figure measurement is the basis to determine the clothing size system. Setting up the model of body fig-ure make the body measurement simplify. Linear regression analysis has been applied to set up the model. While thismethod has lower precision in predicting the clothing detail specification. The gray model theory is applied, with the vari-able height, chest girth and waist girth as independent variables, others as dependent variables, to set up the body figuremodel to determine the detail specification by measuring the major part of the body.%人体尺寸是确定服装规格的客观依据。在人体体型研究过程中，通过人体体型模型建立，由人体的基本部位尺寸来推断其它部位的尺寸，使量体工作得以简化。线性回归分析法曾被应用于人体模型建立，但线性回归分析法对于人体细部规格的预测缺少精度。引进灰色建模理论，在确定身高、胸围、腰围为基本部位下，通过灰色建模过程，建立人体细部规格与基本部位之间的灰色模型关系，从而可以通过基本部位指标预测细部规格，为服装细部规格的确定奠定了基础。
Weird worlds bizarre bodies of the solar system and beyond
Seargent, David A J
2013-01-01
In Weird Worlds, the author discusses planets where temperatures are so high that it rains molten iron, and others so cold that liquid methane floods across plains of ice! Worlds are described where the lightest element acts like a metal and where winds blow at thousands of miles per hour – as well as possible planets whose orbits are essentially parabolic. Weird Worlds is the third book in David Seargent’s “Weird” series. This book assumes a basic level of astronomical understanding and concentrates on the “odd and interesting” aspects of planetary bodies, including asteroids and moons. From our viewpoint here on Earth, this work depicts the most unusual features of these worlds and the ways in which they appear “weird” to us. Within our own Solar System, odd facts such as the apparent reversal of the Sun in the skies of Mercury, CO2-driven fountains of dust on Mars, possible liquid water (and perhaps primitive life!) deep within the dwarf planet Ceres, and a variety of odd facts about ...
MULTI-FLEXIBLE SYSTEM DYNAMIC MODELING THEORY AND APPLICATION
Institute of Scientific and Technical Information of China (English)
仲昕; 周兵; 杨汝清
2001-01-01
The flexible body modeling theory was demonstrated. An example of modeling a kind of automobile's front suspension as a multi-flexible system was shown. Finally, it shows that the simulation results of multi-flexible dynamic model more approach the road test data than those of multi-rigid dynamic model do. Thus, it is fully testified that using multi-flexible body theory to model is necessary and effective.
Study on the Gas Detonation Experimental System of Human Body Electrostatic Discharge
Institute of Scientific and Technical Information of China (English)
2010-01-01
<正>The modeling system of the gas detonation by the human body electrostatic discharge(ESD)in coal mine is developed successfully,and the body’s dynamic ESD model is established.To obtain a gas concentration causes by the explosions most easily in coal mine environment.The results provide an academic and experimental evidence for the safe electrostatic production and management in coal mine.The system adopts 77E58 as control core and the circuit optimized design,to take dual protection to the gas path and circuit of the system,systematic operation is safe and reliable.The experimental results show that the system can be carried out series of experiments of the human body ESD model detonating mixed gas,the measuring accuracy of gas concentration is 0.1%.And draws a conclusion that the gas concentration which causes the explosions most easily is 8.7%,but not the higher gas concentration is,the more explosive is.
Han, Jinxiang; Huang, Jinzhao
2012-03-01
In this study, based on the resonator model and exciplex model of electromagnetic radiation within the human body, mathematical model of biological order state, also referred to as syndrome in traditional Chinese medicine, was established and expressed as: "Sy = v/ 1n(6I + 1)". This model provides the theoretical foundation for experimental research addressing the order state of living system, especially the quantitative research syndrome in traditional Chinese medicine.
Ehsani, Hossein; Rostami, Mostafa; Gudarzi, Mohammad
2016-02-01
Computation of muscle force patterns that produce specified movements of muscle-actuated dynamic models is an important and challenging problem. This problem is an undetermined one, and then a proper optimization is required to calculate muscle forces. The purpose of this paper is to develop a general model for calculating all muscle activation and force patterns in an arbitrary human body movement. For this aim, the equations of a multibody system forward dynamics, which is considered for skeletal system of the human body model, is derived using Lagrange-Euler formulation. Next, muscle contraction dynamics is added to this model and forward dynamics of an arbitrary musculoskeletal system is obtained. For optimization purpose, the obtained model is used in computed muscle control algorithm, and a closed-loop system for tracking desired motions is derived. Finally, a popular sport exercise, biceps curl, is simulated by using this algorithm and the validity of the obtained results is evaluated via EMG signals.
Hatze, Herbert; Baca, Arnold
1993-01-01
The development of noninvasive techniques for the determination of biomechanical body segment parameters (volumes, masses, the three principal moments of inertia, the three local coordinates of the segmental mass centers, etc.) receives increasing attention from the medical sciences (e,.g., orthopaedic gait analysis), bioengineering, sport biomechanics, and the various space programs. In the present paper, a novel method is presented for determining body segment parameters rapidly and accurately. It is based on the video-image processing of four different body configurations and a finite mass-element human body model. The four video images of the subject in question are recorded against a black background, thus permitting the application of shape recognition procedures incorporating edge detection and calibration algorithms. In this way, a total of 181 object space dimensions of the subject's body segments can be reconstructed and used as anthropometric input data for the mathematical finite mass- element body model. The latter comprises 17 segments (abdomino-thoracic, head-neck, shoulders, upper arms, forearms, hands, abdomino-pelvic, thighs, lower legs, feet) and enables the user to compute all the required segment parameters for each of the 17 segments by means of the associated computer program. The hardware requirements are an IBM- compatible PC (1 MB memory) operating under MS-DOS or PC-DOS (Version 3.1 onwards) and incorporating a VGA-board with a feature connector for connecting it to a super video windows framegrabber board for which there must be available a 16-bit large slot. In addition, a VGA-monitor (50 - 70 Hz, horizontal scan rate at least 31.5 kHz), a common video camera and recorder, and a simple rectangular calibration frame are required. The advantage of the new method lies in its ease of application, its comparatively high accuracy, and in the rapid availability of the body segment parameters, which is particularly useful in clinical practice
Dunn, M.; Watson, D. K.; Loeser, J. G.
2006-08-01
In this paper, we develop an analytic N-body wave function for identical particles under quantum confinement with a general two-body interaction. A systematic approach to correlation is developed by combining three theoretical methods: dimensional perturbation theory, the FG method of Wilson et. al., and the group theory of the symmetric group. Analytic results are achieved for a completely general interaction potential. Unlike conventional perturbation methods which are applicable only for weakly interacting systems, this analytic approach is applicable to both weakly and strongly interacting systems. This method directly accounts for each two-body interaction, rather than an average interaction so even lowest-order results include beyond-mean-field effects. One major advantage is that N appears as a parameter in the analytical expressions for the energy so results for different N are easy to obtain.
Wendling, Thierry; Tsamandouras, Nikolaos; Dumitras, Swati; Pigeolet, Etienne; Ogungbenro, Kayode; Aarons, Leon
2016-01-01
Whole-body physiologically based pharmacokinetic (PBPK) models are increasingly used in drug development for their ability to predict drug concentrations in clinically relevant tissues and to extrapolate across species, experimental conditions and sub-populations. A whole-body PBPK model can be fitted to clinical data using a Bayesian population approach. However, the analysis might be time consuming and numerically unstable if prior information on the model parameters is too vague given the complexity of the system. We suggest an approach where (i) a whole-body PBPK model is formally reduced using a Bayesian proper lumping method to retain the mechanistic interpretation of the system and account for parameter uncertainty, (ii) the simplified model is fitted to clinical data using Markov Chain Monte Carlo techniques and (iii) the optimised reduced PBPK model is used for extrapolation. A previously developed 16-compartment whole-body PBPK model for mavoglurant was reduced to 7 compartments while preserving plasma concentration-time profiles (median and variance) and giving emphasis to the brain (target site) and the liver (elimination site). The reduced model was numerically more stable than the whole-body model for the Bayesian analysis of mavoglurant pharmacokinetic data in healthy adult volunteers. Finally, the reduced yet mechanistic model could easily be scaled from adults to children and predict mavoglurant pharmacokinetics in children aged from 3 to 11 years with similar performance compared with the whole-body model. This study is a first example of the practicality of formal reduction of complex mechanistic models for Bayesian inference in drug development.
Neumann, Wladimir; Breuer, Doris; Spohn, Tilman; Henke, Stephan; Gail, Hans-Peter; Schwarz, Winfried; Trieloff, Mario; Hopp, Jens
2015-04-01
The acapulcoites and lodranites are rare groups of achondritic meteorites. Several characteristics such as unique oxygen isotope composition and similar cosmic ray exposure ages indicate that these meteorites originate from a common parent body (Weigel et al. 1999). By contrast to both undifferentiated and differentiated meteorites, acapulcoites and lodranites are especially interesting because they experienced melting that was, however, not complete (McCoy et al. 2006). Thus, unravelling their origin contributes directly to the understanding of the initial differentiation stage of planetary objects in the Solar system. The information preserved in the structure and composition of meteorites can be recovered by modelling the evolution of their parent bodies and comparing the results with the laboratory investigations. Model calculations for the thermal evolution of the parent body of the Acapulco and Lodran-like meteorite clan were performed using two numerical models. Both models (from [3] and [4], termed (a) and (b), respectively) solve a 1D heat conduction equation in spherical symmetry considering heating by short- and long-lived radioactive isotopes, temperature- and porosity-dependent parameters, compaction of initially porous material, and melting. The calculations with (a) were compared to the maximum metamorphic temperatures and thermo-chronological data available for acapulcoites and lodranites. Applying a genetic algorithm, an optimised set of parameters of a common parent body was determined, which fits to the data for the cooling histories of these meteorites. The optimum fit corresponds to a body with the radius of 270 km and a formation time of 1.66 Ma after the CAIs. Using the model by (b) that considers differentiation by porous flow and magmatic heat transport, the differentiation of the optimum fit body was calculated. The resulting structure consists of a metallic core, a silicate mantle, a partially differentiated layer, an undifferentiated
Modeling merging galaxies using MINGA: Improving restricted N-body by dynamical friction
Petsch, H. P.; Theis, Ch.
2008-12-01
Modeling interacting galaxies to reproduce observed systems is still a challenge due to the extended parameter space (among other problems). Orbit and basic galaxy parameters can be tackled by fast simulation techniques like the restricted {N}-body method, applied in the fundamental work by Toomre & Toomre (1972). This approach allows today for the study of millions of models in a short time. One difficulty for the classical restricted {N}-body method is the missing orbital decay, not allowing for galaxy mergers. Here we present an extension of the restricted {N}-body method including dynamical friction. This treatment has been developed by a quantitative comparison with a set of self-consistent merger simulations. By varying the dynamical friction (formalism, strength and direction), we selected the best-fitting parameters for a set of more than 250 000 simulations. We show that our treatment reliably reproduces the orbital decay and tidal features of merging disk galaxies for mass ratios up to q=1/3 between host and satellite. We implemented this technique into our genetic algorithm based modeling code {MINGA} and present first results.
Zhao, Y M; Yoshinaga, N
2002-01-01
In this paper, we discuss the angular momentum distribution in the ground states of many-body systems interacting via a two-body random ensemble. Beginning with a few simple examples, a simple approach to predict P(I)'s, angular momenta I ground state (g.s.) probabilities, of a few solvable cases, such as fermions in a small single-j shell and d boson systems, is given. This method is generalized to predict P(I)'s of more complicated cases, such as even or odd number of fermions in a large single-j shell or a many-j shell, d-boson, sd-boson or sdg-boson systems, etc. By this method we are able to tell which interactions are essential to produce a sizable P(I) in a many-body system. The g.s. probability of maximum angular momentum $I_{max}$ is discussed. An argument on the microscopic foundation of our approach, and certain matrix elements which are useful to understand the observed regularities, are also given or addressed in detail. The low seniority chain of 0 g.s. by using the same set of two-body interact...
Novel simulation model for many-body multipole dispersion interactions
van der Hoef Paul, Martin A.; Madden, A.
We present a novel simulation technique, within the framework of a molecular dynamics simulation, which accounts for both two- and three-body dispersion interactions, up to the triple-quadrupole interaction. This technique involves a unification of molecular dynamics and quantum-mechanical variational methods, in the spirit of the Car-Parrinello method. The advantage of this new method compared to existing techniques for simulating three-body dispersion forces, is that it allows for a consistent treatment of both dispersion damping and periodic boundary conditions at the pair and three-body level. The latter means that it would be possible, for the first time, to include many-body dispersion effects in the simulation of bulk properties of materials, without making use of effective pair potentials.
Mechanical Systems, Classical Models
Teodorescu, Petre P
2009-01-01
This third volume completes the Work Mechanical Systems, Classical Models. The first two volumes dealt with particle dynamics and with discrete and continuous mechanical systems. The present volume studies analytical mechanics. Topics like Lagrangian and Hamiltonian mechanics, the Hamilton-Jacobi method, and a study of systems with separate variables are thoroughly discussed. Also included are variational principles and canonical transformations, integral invariants and exterior differential calculus, and particular attention is given to non-holonomic mechanical systems. The author explains in detail all important aspects of the science of mechanics, regarded as a natural science, and shows how they are useful in understanding important natural phenomena and solving problems of interest in applied and engineering sciences. Professor Teodorescu has spent more than fifty years as a Professor of Mechanics at the University of Bucharest and this book relies on the extensive literature on the subject as well as th...
Liu, Wenyuan; Wang, Chao; Li, Yanbin; Lao, Yuyang; Han, Yongjian; Guo, Guang-Can; Zhao, Yong-Hua; He, Lixin
2015-03-01
Tensor network states (TNS) methods combined with the Monte Carlo (MC) technique have been proven a powerful algorithm for simulating quantum many-body systems. However, because the ground state energy is a highly non-linear function of the tensors, it is easy to get stuck in local minima when optimizing the TNS of the simulated physical systems. To overcome this difficulty, we introduce a replica-exchange molecular dynamics optimization algorithm to obtain the TNS ground state, based on the MC sampling technique, by mapping the energy function of the TNS to that of a classical mechanical system. The method is expected to effectively avoid local minima. We make benchmark tests on a 1D Hubbard model based on matrix product states (MPS) and a Heisenberg J1-J2 model on square lattice based on string bond states (SBS). The results show that the optimization method is robust and efficient compared to the existing results.
A New Nonlinear Model of Body Resistance in Nanometer PD SOI MOSFETs
Directory of Open Access Journals (Sweden)
Arash Daghighi
2011-01-01
Full Text Available In this paper, a nonlinear model for the body resistance of a 45nm PD SOI MOSFET is developed. This model verified on the base of the small signal three-dimensional simulation results. In this paper by using the three-dimensional simulation of ISE-TCAD software, the indicating factors of body resistance in nanometer transistors and then are shown, using the surface potential model. A mathematical relation to calculat the body resistance incorporating device width and body potential was derived. Excellent agreement was obtained by comparing the model outputs and three-dimensional simulation results.
Analysis of Large Flexible Body Deformation in Multibody Systems Using Absolute Coordinates
Energy Technology Data Exchange (ETDEWEB)
Dombrowski, Stefan von [Institute of Robotics and Mechatronics, German Aerospace Center (DLR) (Germany)], E-mail: stefan.von.dombrowski@dlr.de
2002-11-15
To consider large deformation problems in multibody system simulations a finite element approach, called absolute nodal coordinate.formulation,has been proposed. In this formulation absolute nodal coordinates and their material derivatives are applied to represent both deformation and rigid body motion. The choice of nodal variables allows a fully nonlinear representation of rigid body motion and can provide the exact rigid body inertia in the case of large rotations. The methodology is especially suited for but not limited to modeling of beams, cables and shells in multibody dynamics.This paper summarizes the absolute nodal coordinate formulation for a 3D Euler-Bernoulli beam model, in particular the definition of nodal variables, corresponding generalized elastic and inertia forces and equations of motion. The element stiffness matrix is a nonlinear function of the nodal variables even in the case of linearized strain/displacement relations. Nonlinear strain/displacement relations can be calculated from the global displacements using quadrature formulae.Computational examples are given which demonstrate the capabilities of the applied methodology. Consequences of the choice of shape.functions on the representation of internal forces are discussed. Linearized strain/displacement modeling is compared to the nonlinear approach and significant advantages of the latter, when using the absolute nodal coordinate formulation, are outlined.
George, Jeffrey A.
A new nuclear electric propulsion (NEP) systems analysis code is discussed. The new code is modular and consists of a driver code and various subsystem models. The code models five different subsystems: (1) reactor/shield; (2) power conversion; (3) heat rejection; (4) power management and distribution (PMAD); and (5) thrusters. The code optimizes for the following design criteria: minimum mass; minimum radiator area; and low mass/low area. The code also optimizes the following parameters: separation distance; temperature ratio; pressure ratio; and transmission frequency. The discussion is presented in vugraph form.
Santos, L F; Jacquod, P; Kusnezov, Dimitri; Jacquod, Ph.
2002-01-01
We explore generic ground-state and low-energy statistical properties of many-body bosonic and fermionic one- and two-body random ensembles (TBRE) in the dense limit, and contrast them with Random Matrix Theory (RMT). Weak differences in distribution tails can be attributed to the regularity or chaoticity of the corresponding Hamiltonians rather than the particle statistics. We finally show the universality of the distribution of the angular momentum gap between the lowest energy levels in consecutive J-sectors for the four models considered.
The use of the articulated total body model as a robot dynamics simulation tool
Obergfell, Louise A.; Avula, Xavier J. R.; Kalegs, Ints
1988-01-01
The Articulated Total Body (ATB) model is a computer sumulation program which was originally developed for the study of aircrew member dynamics during ejection from high-speed aircraft. This model is totally three-dimensional and is based on the rigid body dynamics of coupled systems which use Euler's equations of motion with constraint relations of the type employed in the Lagrange method. In this paper the use of the ATB model as a robot dynamics simulation tool is discussed and various simulations are demonstrated. For this purpose the ATB model has been modified to allow for the application of torques at the joints as functions of state variables of the system. Specifically, the motion of a robotic arm with six revolute articulations with joint torques prescribed as functions of angular displacement and angular velocity are demonstrated. The simulation procedures developed in this work may serve as valuable tools for analyzing robotic mechanisms, dynamic effects, joint load transmissions, feed-back control algorithms employed in the actuator control and end-effector trajectories.
Multi-body dynamic system simulation of carrier-based aircraft ski-jump takeoff
Institute of Scientific and Technical Information of China (English)
Wang Yangang; Wang Weijun; Qu Xiangju
2013-01-01
The flight safety is threatened by the special flight conditions and the low speed of carrier-based aircraft ski-jump takeoff.The aircraft carrier motion,aircraft dynamics,landing gears and wind field of sea state are comprehensively considered to dispose this multidiscipline intersection problem.According to the particular naval operating environment of the carrier-based aircraft ski-jump takeoff,the integrated dynamic simulation models of multi-body system are developed,which involves the movement entities of the carrier,the aircraft and the landing gears,and involves takeoff instruction,control system and the deck wind disturbance.Based on Matlab/Simulink environment,the multi-body system simulation is realized.The validity of the model and the rationality of the result are verified by an example simulation of carrier-based aircraft ski-jump takeoff.The simulation model and the software are suitable for the study of the multidiscipline intersection problems which are involved in the performance,flight quality and safety of carrier-based aircraft takeoff,the effects of landing gear loads,parameters of carrier deck,etc.
Park, Gwansik; Kim, Taewung; Panzer, Matthew B; Crandall, Jeff R
2016-08-01
In previous shoulder impact studies, the 50th-percentile male GHBMC human body finite-element model was shown to have good biofidelity regarding impact force, but under-predicted shoulder deflection by 80% compared to those observed in the experiment. The goal of this study was to validate the response of the GHBMC M50 model by focusing on three-dimensional shoulder kinematics under a whole-body lateral impact condition. Five modifications, focused on material properties and modeling techniques, were introduced into the model and a supplementary sensitivity analysis was done to determine the influence of each modification to the biomechanical response of the body. The modified model predicted substantially improved shoulder response and peak shoulder deflection within 10% of the observed experimental data, and showed good correlation in the scapula kinematics on sagittal and transverse planes. The improvement in the biofidelity of the shoulder region was mainly due to the modifications of material properties of muscle, the acromioclavicular joint, and the attachment region between the pectoralis major and ribs. Predictions of rib fracture and chest deflection were also improved because of these modifications.
Kumar, D.
1980-01-01
The computer program AFTBDY generates a body fitted curvilinear coordinate system for a wedge curved after body. This wedge curved after body is being used in an experimental program. The coordinate system generated by AFTBDY is used to solve 3D compressible N.S. equations. The coordinate system in the physical plane is a cartesian x,y,z system, whereas, in the transformed plane a rectangular xi, eta, zeta system is used. The coordinate system generated is such that in the transformed plane coordinate spacing in the xi, eta, zeta direction is constant and equal to unity. The physical plane coordinate lines in the different regions are clustered heavily or sparsely depending on the regions where physical quantities to be solved for by the N.S. equations have high or low gradients. The coordinate distribution in the physical plane is such that x stays constant in eta and zeta direction, whereas, z stays constant in xi and eta direction. The desired distribution in x and z is input to the program. Consequently, only the y-coordinate is solved for by the program AFTBDY.
National Energy Modeling System
Energy Technology Data Exchange (ETDEWEB)
Skinner, C.W. (Energy Information Administration, Washington, DC (United States))
1993-01-01
The Energy Information Administration is developing a new National Energy Modeling System to provide annual forecasts of energy supply, demand, and prices on a regional basis in the United States and, to a limited extent, in the rest of the world. The design for the system was based on a requirements analysis, a comparison of requirements with existing modeling capabilities, and a series of widely circulated issue papers defining the choices and tradeoffs for 13 key design decisions. An initial prototpye of the new NEMS was implemented in late 1992, with a more complete, operational version in 1993. NEMS is expected to provide EIA and other users with a greatly enhanced ability to illustrate quickly and effectively the effects of a wide range of energy policy proposals.
The body force in a three-dimensional Lame system identification and regularization
DEFF Research Database (Denmark)
Trong, Dang Duc; Phan, Thanh Nam; Thuc, Phung Trong
2012-01-01
Let a three-dimensional isotropic elastic body be described by the Lamé system with the body force of the form F(x, t) = (t)f (x), where is known. We consider the problem of determining the unknown spatial term f (x) of the body force when the surface stress history is given as the overdeterminat...
Systemic exposure to inhaled beclometasone/formoterol DPI is age and body size dependent
DEFF Research Database (Denmark)
Chawes, B L; Govoni, M; Kreiner-Møller, E;
2014-01-01
normalization for the BDP/formoterol dose in the three populations the AUC and peak concentration (C(max)) correlated inversely with age and body surface area of the patients (r ≤ -0.53; p ... inversely with age and body size suggesting that dry powder dosage regimens should be adjusted for age and body size to avoid high systemic drug levels in children....
Modeling Novo Nordisk Production Systems
DEFF Research Database (Denmark)
Miller, Thomas Dedenroth
1997-01-01
This report describes attributes of models and systems, and how models can be used for description of production systems. There are special attention on the 'Theory of Domains'.......This report describes attributes of models and systems, and how models can be used for description of production systems. There are special attention on the 'Theory of Domains'....
De novo actin polymerization is required for model Hirano body formation in Dictyostelium
Directory of Open Access Journals (Sweden)
Yun Dong
2016-06-01
Full Text Available Hirano bodies are eosinophilic, actin-rich inclusions found in autopsied brains in numerous neurodegenerative diseases. The mechanism of Hirano body formation is unknown. Mass spectrometry analysis was performed to identify proteins from partially purified model Hirano bodies from Dictyostelium. This analysis identified proteins primarily belonging to ribosomes, proteasomes, mitochondria and cytoskeleton. Profilin, Arp/2/3 and WASH identified by mass spectrometry were found to colocalise with model Hirano bodies. Due to their roles in actin regulation, we selected these proteins for further investigation. Inhibition of the Arp2/3 complex by CK666 prevented formation of model Hirano bodies. Since Arp2/3 activation occurs via the WASH or WAVE complex, we next investigated how these proteins affect Hirano body formation. Whereas model Hirano bodies could form in WASH-deficient cells, they failed to form in cells lacking HSPC300, a member of the WAVE complex. We identified other proteins required for Hirano body formation that include profilin and VASP, an actin nucleation factor. In the case of VASP, both its G- and F-actin binding domains were required for model Hirano body formation. Collectively, our results indicate that de novo actin polymerization is required to form model Hirano bodies.
Three-body entanglement induced by spontaneous emission in a three two-level atoms system
Institute of Scientific and Technical Information of China (English)
Liao Xiang-Ping; Fang Mao-Fa; Zheng Xiao-Juan; Cai Jian-Wu
2006-01-01
We study three-body entanglement induced by spontaneous emission in a three two-level atoms system by using the entanglement tensor approach. The results show that the amount of entanglement is strongly dependent on the initial state of the system and the species of atoms. The three-body entanglement is the result of the coherent superposition of the two-body entanglements. The larger the two-body entanglement is, the stronger the three-body entanglement is. On the other hand, if there exists a great difference in three two-body entanglement measures, the three-body entanglement is very weak. We also find that the maximum of the two-body entanglement obtained with nonidentical atoms is greater than that obtained with identical atoms via adjusting the difference in atomic frequency.
Tedeschi, Luis O; Fox, Danny G; Kononoff, Paul J
2013-04-01
The objective of this paper was to develop the structure and concepts of a dynamic model to simulate dry matter intake (DMI) pattern and the fluxes of fat and protein in the body reserves of cattle associated with changes in body condition score (BCS) for application within the structure of applied nutrition models. This model was developed to add the capability of evaluating the effects of factors affecting pre- and postcalving DMI, daily energy and protein balances, and changes in BCS over a reproductive cycle. Input variables are average DMI, diet metabolizable energy, and animal information (body weight, BCS, milk production, and calf birth body weight) from each diet fed over the reproductive cycle. Because the depletion and repletion of body reserves in cattle is a complex system of coordinated metabolic processes that reflect hormonal and physiological changes caused by negative or positive energy balances, the system dynamics modeling methodology was used to develop this model. The model was used to evaluate the effect of the dynamic interactions between dietary supply and animal requirements for energy and protein on the fluxes of body fat and body protein of dairy cows over the reproductive cycle and Monte Carlo simulations were used to assess the sensitivity of the parameters. The main long-term factor affecting DMI pattern was the growth of the gravid uterus causing an increase in the volume of abdominal organs and a compression of the rumen, consequentially reducing feed intake. Changes in body reserves (fat and protein) were computed based on metabolizable energy balance, assuming different efficiency of utilization coefficients for fat and protein during repletion and mobilization. The model was evaluated with data from 37 dairy cows individually fed 3 different diets over the lactation and dry periods. The model was successful in simulating the observed pattern of DMI (mean square error was 3.59, 3.97, and 3.66 for diets A, B, and C, respectively
Photochemical hazes in planetary atmospheres: solar system bodies and beyond
Imanaka, Hiroshi; Cruikshank, Dale P.; McKay, Christopher P.
2015-11-01
Recent transit observations of exoplanets have demonstrated the possibility of a wide prevalence of haze/cloud layers at high altitudes. Hydrocarbon photochemical haze could be the candidate for such haze particles on warm sub-Neptunes, but the lack of evidence for methane poses a puzzle for such hydrocarbon photochemical haze. The CH4/CO ratios in planetary atmospheres vary substantially from their temperature and dynamics. An understanding of haze formation rates and plausible optical properties in a wide diversity of planetary atmospheres is required to interpret the current and future observations.Here, we focus on how atmospheric compositions, specifically CH4/CO ratios, affect the haze production rates and their optical properties. We have conducted a series of cold plasma experiments to constrain the haze mass production rates from gas mixtures of various CH4/CO ratios diluted either in H2 or N2 atmosphere. The mass production rates in the N2-CH4-CO system are much greater than those in the H2-CH4-CO system. They are rather insensitive to the CH4/CO ratios larger than at 0.3. Significant formation of solid material is observed both in H2-CO and N2-CO systems without CH4 in the initial gas mixtures. The complex refractive indices were derived for haze samples from N2-CH4, H2-CH4, and H2-CO gas mixtures. These are the model atmospheres for Titan, Saturn, and exoplanets, respectively. The imaginary part of the complex refractive indices in the UV-Vis region are distinct among these samples, which can be utilized for modeling these planetary atmospheres.
Three-body recombination at finite energy within an optical model
DEFF Research Database (Denmark)
Sørensen, Peder Klokmose; V. Fedorov, D.; S. Jensen, A.;
2013-01-01
We investigate three-boson recombination of equal mass systems as function of (negative) scattering length, mass, finite energy, and finite temperature. An optical model with an imaginary potential at short distance reproduces experimental recombination data and allows us to provide a simple...... parametrization of the recombination rate as function of scattering length and energy. Using the two-body van der Waals length as unit we find that the imaginary potential range and also the potential depth agree to within thirty percent for Lithium and Cesium atoms. As opposed to recent studies suggesting...
Modeling Merging Galaxies using MINGA - Improving Restricted N-body by Dynamical Friction
Petsch, Hanns P
2008-01-01
Modeling interacting galaxies to reproduce observed systems is still a challenge due to the extended parameter space (among other problems). Orbit and basic galaxy parameters can be tackled by fast simulation techniques like the restricted N-body method, applied in the fundamental work by Toomre & Toomre (1972). This approach allows today for the study of millions of models in a short time. One difficulty for the classical restricted N-body method is the missing orbital decay, not allowing for galaxy mergers. Here we present an extension of the restricted N-body method including dynamical friction. This treatment has been developed by a quantitative comparison with a set of self-consistent merger simulations. By varying the dynamical friction (formalism, strength and direction), we selected the best-fitting parameters for a set of more than 250000 simulations. We show that our treatment reliably reproduces the orbital decay and tidal features of merging disk galaxies for mass ratios up to q=1/3 between ho...
A new 3D reconstruction method of small solar system bodies
Capanna, C.; Jorda, L.; Lamy, P.; Gesquiere, G.
2011-10-01
The 3D reconstruction of small solar system bodies consitutes an essential step toward understanding and interpreting their physical and geological properties. We propose a new reconstruction method by photoclinometry based on the minimization of the chisquare difference between observed and synthetic images by deformation of a 3D triangular mesh. This method has been tested on images of the two asteroids (2867) Steins and (21) Lutetia observed during ESA's ROSETTA mission, and it will be applied to elaborate digital terrain models from images of the asteroid (4) Vesta, the target of NASA's DAWN spacecraft.
Equivalent dynamical complexity in a many-body quantum and collective human system
Directory of Open Access Journals (Sweden)
Neil F. Johnson
2011-03-01
Full Text Available Proponents of Complexity Science believe that the huge variety of emergent phenomena observed throughout nature, are generated by relatively few microscopic mechanisms. Skeptics however point to the lack of concrete examples in which a single mechanistic model manages to capture relevant macroscopic and microscopic properties for two or more distinct systems operating across radically different length and time scales. Here we show how a single complexity model built around cluster coalescence and fragmentation, can cross the fundamental divide between many-body quantum physics and social science. It simultaneously (i explains a mysterious recent finding of Fratini et al. concerning quantum many-body effects in cuprate superconductors (i.e. scale of 10−9 − 10−4 meters and 10−12 − 10−6 seconds, (ii explains the apparent universality of the casualty distributions in distinct human insurgencies and terrorism (i.e. scale of 103 − 106 meters and 104 − 108 seconds, (iii shows consistency with various established empirical facts for financial markets, neurons and human gangs and (iv makes microscopic sense for each application. Our findings also suggest that a potentially productive shift can be made in Complexity research toward the identification of equivalent many-body dynamics in both classical and quantum regimes.
An Iterative Method for the Construction of Equilibrium N-Body Models for Stellar Disks
Rodionov, S A
2006-01-01
One widely used technique for the construction of equilibrium models of stellar disks is based on the Jeans equations and the moments of velocity distribution functions derived using these equations. Stellar disks constructed using this technique are shown to be "not entirely" in equilibrium. Our attempt to abandon the epicyclic approximation and the approximation of infinite isothermal layers, which are commonly adopted in this technique, failed to improve the situation substantially. We conclude that the main drawback of techniques based on the Jeans equations is that the system of equations employed is not closed, and therefore requires adopting an essentially ad hoc additional closure condition. A new iterative approach to constructing equilibrium N-body models with a given density distribution is proposed. The main idea behind this approach is that a model is first constructed using some approximation method, and is then allowed to adjust to an equilibrium state with the specified density and the require...
Three- and four-body systems with the Functional Renormalization Group
Raziel, Benjamín; Ávila, Jaramillo
2016-10-01
The Efimov effect arises in three-body systems near the unitary limit. Some of its features are universal, while others are not. This article uses a Functional-Renormalization- Group approach to discuss the Efimov effect and four-body systems. In this context, the Efimov effect appears as a consequence of the Renormalization-Group flow of couplings. On the four- body system, we find three tetramers below each Efimov trimer, and no evidence of four- body universality breaking. Two of these tetramers are in agreement with quantum-mechanical calculations and experimental results.
Structure of the body-centered cubic phase of lipid systems.
Saludjian, P; Reiss-Husson, F
1980-12-01
A new model is proposed for the structure of the body-centered cubic phase of lipid systems. Infinite rods of polar groups (and water) are arranged with axes parallel to the four cubic [unk]1 1 1[unk] directions. The hydrocarbon chains fill the space between the rods to form a continuous matrix. With this unified topology, the model explains satisfactorily the x-ray diffraction patterns of strontium soaps, lecithin, galactolipids, potassium soaps, and hexadecyltrimethylammonium bromide and explains the transition between cubic/H(II) phases. The paradoxical thermal effects on the lipid cubic phase, in particular the decrease of unit cell dimensions with increasing temperature, can be explained with the proposed model by mechanisms similar to those used for the monodimensional and bidimensional (mesomorphic) phases.
Two bodies gravitational system with variable mass and damping-antidamping effect due to star wind
López, G V
2009-01-01
We study two-bodies gravitational problem where the mass of one of the bodies varies and suffers a damping-antidamping effect due to star wind during its motion. A constant of motion, a Lagrangian and a Hamiltonian are given for the radial motion of the system, and the period of the body is studied using the constant of motion of the system. An application to the comet motion is given, using the comet Halley as an example.
Reduced Order Aeroservoelastic Models with Rigid Body Modes Project
National Aeronautics and Space Administration — Complex aeroelastic and aeroservoelastic phenomena can be modeled on complete aircraft configurations generating models with millions of degrees of freedom. Starting...
DEFF Research Database (Denmark)
Christensen, Louise Dahl; Moser, Claus; Jensen, Peter Ø;
2007-01-01
of growth contributes significantly to P. aeruginosa tolerance to the action of the innate and adaptive defence system and numerous antibiotics. In the present study, an in vivo foreign-body infection model was established in the peritoneal cavity of mice. Experimental data showed that QS-deficient P...
Arampatzis, A; Brüggemann, G P
1998-12-01
The aims of this study were: 1. To study the transfer of energy between the high bar and the gymnast. 2. To develop criteria from the utilisation of high bar elasticity and the utilisation of muscle capacity to assess the effectiveness of a movement solution. 3. To study the influence of varying segment movement upon release parameters. For these purposes a model of the human body attached to the high bar (high bar-human body model) was developed. The human body was modelled using a 15-segment body system. The joint-beam element method (superelement) was employed for modelling the high bar. A superelement consists of four rigid segments connected by joints (two Cardan joints and one rotational-translational joint) and springs (seven rotation springs and one tension-compression spring). The high bar was modelled using three superelements. The input data required for the high bar human body model were collected with video-kinematographic (50 Hz) and dynamometric (500 Hz) techniques. Masses and moments of inertia of the 15 segments were calculated using the data from the Zatsiorsky et al. (1984) model. There are two major phases characteristic of the giant swing prior to dismounts from the high bar. In the first phase the gymnast attempts to supply energy to the high bar-humanbody system through muscle activity and to store this energy in the high bar. The difference between the energy transferred to the high bar and the reduction in the total energy of the body could be adopted as a criterion for the utilisation of high bar elasticity. The energy previously transferred into the high bar is returned to the body during the second phase. An advantageous increase in total body energy at the end of the exercise could only be obtained through muscle energy supply. An index characterising the utilisation of muscle capacity was developed out of the difference between the increase in total body energy and the energy returned from the high bar. A delayed and initially slow but
Dynamics of isolated quantum systems: many-body localization and thermalization
Torres-Herrera, E. Jonathan; Tavora, Marco; Santos, Lea F.
2016-05-01
We show that the transition to a many-body localized phase and the onset of thermalization can be inferred from the analysis of the dynamics of isolated quantum systems taken out of equilibrium abruptly. The systems considered are described by one-dimensional spin-1/2 models with static random magnetic fields and by power-law band random matrices. We find that the short-time decay of the survival probability of the initial state is faster than exponential for sufficiently strong perturbations. This initial evolution does not depend on whether the system is integrable or chaotic, disordered or clean. At long-times, the dynamics necessarily slows down and shows a power-law behavior. The value of the power-law exponent indicates whether the system will reach thermal equilibrium or not. We present how the properties of the spectrum, structure of the initial state, and number of particles that interact simultaneously affect the value of the power-law exponent. We also compare the results for the survival probability with those for few-body observables. EJTH aknowledges financial support from PRODEP-SEP and VIEP-BUAP, Mexico.
Testing lowered isothermal models with direct N-body simulations of globular clusters
Zocchi, Alice; Gieles, Mark; Hénault-Brunet, Vincent; Varri, Anna Lisa
2016-10-01
Several self-consistent models have been proposed, aiming at describing the phase-space distribution of stars in globular clusters. This study explores the ability of the recently proposed LIMEPY models to reproduce the dynamical properties of direct N-body models of a cluster in a tidal field, during its entire evolution. These dynamical models include prescriptions for the truncation and the degree of radially biased anisotropy contained in the system, allowing us to explore the interplay between the role of anisotropy and tides in various stages of the life of star clusters. We show that the amount of anisotropy in an initially tidally underfilling cluster increases in the pre-collapse phase, and then decreases with time, due to the effect of the external tidal field on its spatial truncation. This is reflected in the correspondent model parameters, and the best-fitting models reproduce the main properties of the cluster at all stages of its evolution, except for the phases immediately preceding and following core collapse. We also notice that the best-fitting LIMEPY models are significantly different from isotropic King models, especially in the first part of the evolution of the cluster. Our results put limits on the amount of radial anisotropy that can be expected for clusters evolving in a tidal field, which is important to understand other factors that could give rise to similar observational signatures, such as the presence of an intermediate-mass black hole.
78 FR 72571 - Extension of Expiration Date for Mental Disorders Body System Listings
2013-12-03
... ADMINISTRATION 20 CFR Part 404 RIN 0960-AH49 Extension of Expiration Date for Mental Disorders Body System... expiration date of the Mental Disorders body system in the Listing of Impairments (listings) in our... ensure that we continue to have the criteria we need to evaluate mental disorders at step three of...
Single-particle properties in an exactly solvable A-body system
VanNeck, D; Dieperink, AEL; Waroquier, M
1996-01-01
A recent theorem states that for quantum many-body systems with short-range interactions the following property holds: the single-particle overlap functions, spectroscopic factors and separation energies of bound eigenstates of the (A - 1)-particle system are fully determined by the one-body density
77 FR 35264 - Extension of Expiration Dates for Several Body System Listings
2012-06-13
... ADMINISTRATION 20 CFR Part 404 RIN 0960-AH49 Extension of Expiration Dates for Several Body System Listings... dates of the following body systems in the Listing of Impairments (listings) in our regulations: Growth... evaluation processes for initial claims and continuing disability reviews. DATES: This final rule...
Three-body recombination of two-component cold atomic gases into deep dimers in an optical model
DEFF Research Database (Denmark)
Mikkelsen, Mathias; Jensen, A. S.; Fedorov, D. V.
2015-01-01
We consider three-body recombination into deep dimers in a mass-imbalanced two-component atomic gas. We use an optical model where a phenomenological imaginary potential is added to the lowest adiabatic hyper-spherical potential. The consequent imaginary part of the energy eigenvalue corresponds...... to the decay rate or recombination probability of the three-body system. The method is formulated in details and the relevant qualitative features are discussed as functions of scattering lengths and masses. We use zero-range model in analyses of recent recombination data. The dominating scattering length...
A New Treatment Below the Three-Body Break up Threshold in the NNπ System
Directory of Open Access Journals (Sweden)
Oryu Shinsho
2016-01-01
Full Text Available The two-body threshold behavior at NN′ and πD are investigated by using the multi-channel Lippmann-Schwinger equations with an energy dependent two-body quasi potential, which are analytically continued from the three-body Faddeev equations at the three-body break up threshold. Our calculated NN′ and πD scattering lengths show better agreement with the experimental data for NN and πD systems than those from the original NNπ three-body Faddeev equations.
A method for geometric modelling of magnetic anomalies: Two dimensional bodies
Digital Repository Service at National Institute of Oceanography (India)
Rao, T.C.S.
dimensional bodies like cylinders, dykes and steps etc. Careful examination of the existing methods for computing the magnetic anomalies reveals that different fonnulae are employed for bodies ofdifferent shapes. These have been used to get satisfactory fit... equal and the throw of the step model would become the width of the vertical dyke model (D ;; 90°). However, the comer 2 of the body is located to the left of corner 1 and is 180· out of phase. Therefore, the body in Fig. 2B has to 22 -----..:'r-,.. I Po...
Chaos and irreversibility in simple model systems.
Hoover, Wm. G.; Posch, Harald A.
1998-06-01
The multifractal link between chaotic time-reversible mechanics and thermodynamic irreversibility is illustrated for three simple chaotic model systems: the Baker Map, the Galton Board, and many-body color conductivity. By scaling time, or the momenta, or the driving forces, it can be shown that the dissipative nature of the three thermostated model systems has analogs in conservative Hamiltonian and Lagrangian mechanics. Links between the microscopic nonequilibrium Lyapunov spectra and macroscopic thermodynamic dissipation are also pointed out. (c) 1998 American Institute of Physics.
Space weathering and the color indexes of minor bodies in the outer Solar System
Kaňuchová, Zuzana; Brunetto, Rosario; Melita, Mario; Strazzulla, Giovanni
2012-09-01
The surfaces of small bodies in the outer Solar System are rich in organic compounds and carbonaceous refractories mixed with ices and silicates. As made clear by dedicated laboratory experiments space weathering (e.g. energetic ion bombardment) can produce red colored materials starting from bright and spectrally flat ices. In a classical scenario, the space weathering processes “nurture” alter the small bodies surface spectra but are in competition with resurfacing agents that restore the original colors, and the result of these competing processes continuously modifying the surfaces is supposed to be responsible for the observed spectral variety of those small bodies. However an alternative point of view is that the different colors are due to “nature” i.e. to the different primordial composition of different objects. In this paper we present a model, based on laboratory results, that gives an original contribution to the “nature” vs. “nurture” debate by addressing the case of surfaces showing different fractions of rejuvenated vs. space weathered surface, and calculating the corresponding color variations. We will show how a combination of increasing dose coupled to different resurfacing can reproduce the whole range of observations of small outer Solar System bodies. Here we demonstrate, for the first time that objects having a fully weathered material turn back in the color-color diagrams. At the same time, object with the different ratio of pristine and weathered surface areas lay on specific lines in color-color diagrams, if exposed to the same amount of irradiation.
Body image concerns in professional fashion models: are they really an at-risk group?
Swami, Viren; Szmigielska, Emilia
2013-05-15
Although professional models are thought to be a high-risk group for body image concerns, only a handful of studies have empirically investigated this possibility. The present study sought to overcome this dearth of information by comparing professional models and a matched sample on key indices of body image and appeared-related concerns. A group of 52 professional fashion models was compared with a matched sample of 51 non-models from London, England, on indices of weight discrepancy, body appreciation, social physique anxiety, body dissatisfaction, drive for thinness, internalization of sociocultural messages about appearance, and dysfunctional investment in appearance. Results indicated that professional models only evidenced significantly higher drive for thinness and dysfunctional investment in appearance than the control group. Greater duration of engagement as a professional model was associated with more positive body appreciation but also greater drive for thinness. These results indicate that models, who are already underweight, have a strong desire to maintain their low body mass or become thinner. Taken together, the present results suggest that interventions aimed at promoting healthy body image among fashion models may require different strategies than those aimed at the general population.
Hase, Kazunori; Yamazaki, Nobutoshi
A model having a three-dimensional entire-body structure and consisting of both the neuronal system and the musculo-skeletal system was proposed to precisely simulate human walking motion. The dynamics of the human body was represented by a 14-rigid-link system and 60 muscular models. The neuronal system was represented by three sub-systems: the rhythm generator system consisting of 32 neural oscillators, the sensory feedback system, and the peripheral system expressed by static optimization. Unknown neuronal parameters were adjusted by a numerical search method using the evaluative criterion for locomotion that was defined by a hybrid between the locomotive energy efficiency and the smoothness of the muscular tensions. The model could successfully generate continuous and three-dimensional walking patterns and stabilized walking against mechanical perturbation. The walking pattern was more stable than that of the model based on dynamic optimization, and more precise than that of the previous model based on a similar neuronal system.
Evolution of star cluster systems in isolated galaxies: first results from direct N-body simulations
Rossi, L. J.; Bekki, K.; Hurley, J. R.
2016-11-01
The evolution of star clusters is largely affected by the tidal field generated by the host galaxy. It is thus in principle expected that under the assumption of a `universal' initial cluster mass function the properties of the evolved present-day mass function of star cluster systems should show a dependence on the properties of the galactic environment in which they evolve. To explore this expectation, a sophisticated model of the tidal field is required in order to study the evolution of star cluster systems in realistic galaxies. Along these lines, in this work we first describe a method developed for coupling N-body simulations of galaxies and star clusters. We then generate a data base of galaxy models along the Hubble sequence and calibrate evolutionary equations to the results of direct N-body simulations of star clusters in order to predict the clusters' mass evolution as function of the galactic environment. We finally apply our methods to explore the properties of evolved `universal' initial cluster mass functions and any dependence on the host galaxy morphology and mass distribution. The preliminary results show that an initial power-law distribution of the masses `universally' evolves into a lognormal distribution, with the properties correlated with the stellar mass and stellar mass density of the host galaxy.
Equilibrium points in the restricted synchronous three-body problem using a mass dipole model
Barbosa Torres dos Santos, Leonardo; Bertachini de Almeida Prado, Antonio F.; Merguizo Sanchez, Diogo
2017-03-01
The objective of the present paper is to investigate the zero velocity curves, using the Jacobi constant C, and to determine the positions of the libration points in the restricted synchronous three-body problem. To perform this task, it is necessary to obtain the equations of motion of a negligible mass traveling in a system composed of two other massive bodies. One of them is assumed to have a spherical shape, while the other one is irregular shaped and modeled as a rotating mass dipole. The locations of the equilibrium points are determined and then, for several values C of the Jacobi constant, the boundary regions are obtained where the motion of the particle is allowed. The zero velocity curves are plotted. Next, the stability of these equilibrium points examined, including the collinear and non-collinear ones. It is found that the collinear points are unstable and the non-collinear ones are linearly stable for lower values of the mass parameter. A comparison with the equivalent results for the dynamics considering three points of mass is made, to emphasize the influence of the elongation of one of the bodies.
Directory of Open Access Journals (Sweden)
Monica Neagu
2013-01-01
Full Text Available A cutaneous melanoma mouse model was used to test the efficacy of a new therapeutical approach that uses low doses of cytostatics in conjunction with mild whole body microwave exposure of 2.45 GHz in order to enhance cytostatics antitumoral effect. Materials and Methods. A microwave exposure system for C57BL/6 mouse whole body microwave irradiation was designed; groups of 40 mice (males and females bearing experimental tumours were subjected to a combined therapy comprising low doses of dacarbazine in combination with mild whole body irradiation. Clinical parameters and serum cytokine testing using xMAP technology were performed. Results. The group that was subjected to combined therapy, microwave and cytostatic, had the best clinical evolution in terms of overall survival, tumour volume, and metastatic potential. At day 14 the untreated group had 100% mortality, while in the combined therapy group 40% of mice were surviving. Quantifying serum IL-1β, IL-6, IL-10, IL-12 (p70, IFN-γ, GM-CSF, TNF-α, MIP-1α, MCP-1, and KC during tumorigenesis and therapy found that the combined experimental therapy decreases all the inflammatory cytokines, except chemokine MCP-1 that was found increased, suggesting an increase of the anti-tumoral immune response triggered by the combined therapy. The overall metastatic process is decreased in the combined therapy group.
Effective-one-body waveforms for binary neutron stars using surrogate models
Lackey, Benjamin D; Galley, Chad R; Meidam, Jeroen; Broeck, Chris Van Den
2016-01-01
Gravitational-wave observations of binary neutron star systems can provide information about the masses, spins, and structure of neutron stars. However, this requires accurate and computationally efficient waveform models that take <1s to evaluate for use in Bayesian parameter estimation codes that perform 10^7 - 10^8 waveform evaluations. We present a surrogate model of a nonspinning effective-one-body waveform model with l = 2, 3, and 4 tidal multipole moments that reproduces waveforms of binary neutron star numerical simulations up to merger. The surrogate is built from compact sets of effective-one-body waveform amplitude and phase data that each form a reduced basis. We find that 12 amplitude and 7 phase basis elements are sufficient to reconstruct any binary neutron star waveform with a starting frequency of 10Hz. The surrogate has maximum errors of 3.8% in amplitude (0.04% excluding the last 100M before merger) and 0.043 radians in phase. The version implemented in the LIGO Algorithm Library takes ~...
Long-distance entanglement in many-body atomic and optical systems
Energy Technology Data Exchange (ETDEWEB)
Giampaolo, Salvatore M; Illuminati, Fabrizio [Dipartimento di Matematica e Informatica, Universita degli Studi di Salerno, Via Ponte don Melillo, I-84084 Fisciano, SA (Italy)], E-mail: illuminati@sa.infn.it
2010-02-15
We discuss the phenomenon of long-distance entanglement (LDE) in the ground state of quantum spin models, its use in high-fidelity and robust quantum communication, and its realization in many-body systems of ultracold atoms in optical lattices and in arrays of coupled optical cavities. We investigate XX quantum spin models on one-dimensional lattices with open ends and different patterns of site-dependent interaction couplings, singling out two general settings: patterns that allow for perfect LDE in the ground state of the system, namely such that the end-to-end entanglement remains finite in the thermodynamic limit, and patterns of quasi-long-distance entanglement (QLDE) in the ground state of the system, namely such that the end-to-end entanglement vanishes with a very slow power-law decay as the length of the spin chain is increased. We discuss physical realizations of these models in ensembles of ultracold bosonic atoms loaded in optical lattices. We show how, using either suitably engineered super-lattice structures or exploiting the presence of edge impurities in lattices with single periodicity, it is possible to realize models endowed with nonvanishing LDE or QLDE. We then study how to realize models that optimize the robustness of QLDE at finite temperature and in the presence of imperfections using suitably engineered arrays of coupled optical cavities. For both cases the numerical estimates of the end-to-end entanglement in the actual physical systems are thoroughly compared with the analytical results obtained for the spin model systems. We finally introduce LDE-based schemes of long-distance quantum teleportation in linear arrays of coupled cavities, and show that they allow for high-fidelity and high success rates even at moderately high temperatures.
Choi, Seung-Bok; Han, Young-Min
2007-06-01
This paper presents vibration control performance of a semi-active electrorheological (ER) seat suspension system using a robust sliding mode controller (SMC). A cylindrical type of ER seat damper is manufactured for a commercial vehicle seat suspension and its field-dependent damping force is experimentally evaluated. A vertical vibration model of human-body is then derived and integrated with the governing equations of the ER seat suspension system. The integrated seat-driver model featured by a high order degree-of-freedom (dof) is reduced through a balanced model reduction method. The SMC is then designed based on the reduced model and the state observer is formulated to estimate feedback states which cannot be directly measured from sensors. By imposing a semi-active actuating condition, the synthesized SMC is experimentally realized. In the experimental implementation, a driver directly sits on the controlled seat. Both vertical displacement and acceleration are measured at seat frame and driver's head, respectively. Control performances are evaluated under various road conditions and compared with those obtained from conventional passive seat suspension system.
A quantum information perspective of fermionic quantum many-body systems
Energy Technology Data Exchange (ETDEWEB)
Kraus, Christina V.
2009-11-02
In this Thesis fermionic quantum many-body system are theoretically investigated from a quantum information perspective. Quantum correlations in fermionic many-body systems, though central to many of the most fascinating effects of condensed matter physics, are poorly understood from a theoretical perspective. Even the notion of ''paired'' fermions which is widely used in the theory of superconductivity and has a clear physical meaning there, is not a concept of a systematic and mathematical theory so far. Applying concepts and tools from entanglement theory, we close this gap, developing a pairing theory allowing to unambiguously characterize paired states. We develop methods for the detection and quantification of pairing according to our definition which are applicable to current experimental setups. Pairing is shown to be a quantum correlation distinct from any notion of entanglement proposed for fermionic systems, giving further understanding of the structure of highly correlated quantum states. In addition, we show the resource character of paired states for precision metrology, proving that BCS-states allow phase measurements at the Heisenberg limit. Next, the power of fermionic systems is considered in the context of quantum simulations, where we study the possibility to simulate Hamiltonian time evolutions on a cubic lattice under the constraint of translational invariance. Given a set of translationally invariant local Hamiltonians and short range interactions we determine time evolutions which can and those which can not be simulated. Bosonic and finite-dimensional quantum systems (''spins'') are included in our investigations. Furthermore, we develop new techniques for the classical simulation of fermionic many-body systems. First, we introduce a new family of states, the fermionic Projected Entangled Pair States (fPEPS) on lattices in arbitrary spatial dimension. These are the natural generalization of the PEPS
Impact of variable body size on pedestrian dynamics by heuristics-based model
Guo, Ning; Hu, Mao-Bin; Jiang, Rui
2017-01-01
In the real world, pedestrians can arch the shoulders or rotate their bodies actively to across the narrow space. The method is helpful to reduce the effective size of the body. In this paper, the impact of variable body size on the direction choice has been investigated by an improved heuristic-based model. In the model, it is assumed that the cost of adjusting body size is a factor in the process to evaluate the optimal direction. In a typical simulation scenario, the pedestrian reluctant to adjust body size will pass by the blocks. On the contrary, the pedestrian caring little about body size will traverse through the exit. There is a direction-choice change behavior between bypass and traverse considering block width and the initial location of the pedestrian.
Yoga and positive body image: A test of the Embodiment Model.
Mahlo, Leeann; Tiggemann, Marika
2016-09-01
The study aimed to test the Embodiment Model of Positive Body Image (Menzel & Levine, 2011) within the context of yoga. Participants were 193 yoga practitioners (124 Iyengar, 69 Bikram) and 127 university students (non-yoga participants) from Adelaide, South Australia. Participants completed questionnaire measures of positive body image, embodiment, self-objectification, and desire for thinness. Results showed yoga practitioners scored higher on positive body image and embodiment, and lower on self-objectification than non-yoga participants. In support of the embodiment model, the relationship between yoga participation and positive body image was serially mediated by embodiment and reduced self-objectification. Although Bikram practitioners endorsed appearance-related reasons for participating in yoga more than Iyengar practitioners, there were no significant differences between Iyengar and Bikram yoga practitioners on body image variables. It was concluded that yoga is an embodying activity that can provide women with the opportunity to cultivate a favourable relationship with their body.
a Modal Analysis of Whole-Body Vertical Vibration, Using a Finite Element Model of the Human Body
Kitazaki, S.; Griffin, M. J.
1997-02-01
A two-dimensional model of human biomechanical responses to whole-body vibration has been developed, by using the finite element method. Beam, spring and mass elements were used to model the spine, viscera, head, pelvis and buttocks tissue in the mid-sagittal plane. The model was developed by comparison of the vibration mode shapes with those previously measured in the laboratory. At frequencies below 10 Hz, the model produced seven modes which coincided well with the measurements. The principal resonance of the driving point response at about 5 Hz consisted of an entire body mode, in which the head, spinal column and the pelvis move almost rigidly, with axial and shear deformation of tissue beneath the pelvis occurring in phase with a vertical visceral mode. The second principal resonance at about 8 Hz corresponded to a rotational mode of the pelvis, with a possible contribution from a second visceral mode. A shift of the principal resonance of the driving point response, when changing posture, was achieved only by changing the axial stiffness of the buttocks tissue. It is suggested that an increase in contact area between the buttocks and the thighs and the seat surface, when changing posture from erect to slouched, may decrease the axial stiffness beneath the pelvis, with a non-linear force-deflection relationship of tissue resulting in decreases in the natural frequencies. A change in posture from erect to slouched also increased shear deformation of tissue beneath the pelvis in the entire body mode, and the natural frequency was decreased as a result of the much lower shear stiffness of tissue compared to the axial stiffness.
Waif goodbye! Average-size female models promote positive body image and appeal to consumers.
Diedrichs, Phillippa C; Lee, Christina
2011-10-01
Despite consensus that exposure to media images of thin fashion models is associated with poor body image and disordered eating behaviours, few attempts have been made to enact change in the media. This study sought to investigate an effective alternative to current media imagery, by exploring the advertising effectiveness of average-size female fashion models, and their impact on the body image of both women and men. A sample of 171 women and 120 men were assigned to one of three advertisement conditions: no models, thin models and average-size models. Women and men rated average-size models as equally effective in advertisements as thin and no models. For women with average and high levels of internalisation of cultural beauty ideals, exposure to average-size female models was associated with a significantly more positive body image state in comparison to exposure to thin models and no models. For men reporting high levels of internalisation, exposure to average-size models was also associated with a more positive body image state in comparison to viewing thin models. These findings suggest that average-size female models can promote positive body image and appeal to consumers.
Vermeeren, Günter; Joseph, Wout; Martens, Luc
2013-04-01
Assessing the whole-body absorption in a human in a realistic environment requires a statistical approach covering all possible exposure situations. This article describes the development of a statistical multi-path exposure method for heterogeneous realistic human body models. The method is applied for the 6-year-old Virtual Family boy (VFB) exposed to the GSM downlink at 950 MHz. It is shown that the whole-body SAR does not differ significantly over the different environments at an operating frequency of 950 MHz. Furthermore, the whole-body SAR in the VFB for multi-path exposure exceeds the whole-body SAR for worst-case single-incident plane wave exposure by 3.6%. Moreover, the ICNIRP reference levels are not conservative with the basic restrictions in 0.3% of the exposure samples for the VFB at the GSM downlink of 950 MHz. The homogeneous spheroid with the dielectric properties of the head suggested by the IEC underestimates the absorption compared to realistic human body models. Moreover, the variation in the whole-body SAR for realistic human body models is larger than for homogeneous spheroid models. This is mainly due to the heterogeneity of the tissues and the irregular shape of the realistic human body model compared to homogeneous spheroid human body models.
An anatomically shaped lower body model for CT scanning of cadaver femurs
Energy Technology Data Exchange (ETDEWEB)
Tanck, Esther; Deenen, J C W; Verdonschot, Nico [Orthopaedic Research Laboratory, Radboud University Nijmegen Medical Center, PO Box 9101, 6500 HB Nijmegen (Netherlands); Huisman, Henk Jan [Department of Radiology, Radboud University Nijmegen Medical Center, Nijmegen (Netherlands); Kooloos, Jan G [Department of Anatomy, Radboud University Nijmegen Medical Center, Nijmegen (Netherlands); Huizenga, Henk [Department of Radiotherapy, Radboud University Nijmegen Medical Center, Nijmegen (Netherlands)], E-mail: e.tanck@orthop.umcn.nl
2010-01-21
Bone specific, CT-based finite element (FE) analyses have great potential to accurately predict the fracture risk of deteriorated bones. However, it has been shown that differences exist between FE-models of femora scanned in a water basin or scanned in situ within the human body, as caused by differences in measured bone mineral densities (BMD). In this study we hypothesized that these differences can be reduced by re-creating the patient CT-conditions by using an anatomically shaped physical model of the lower body. BMD distributions were obtained from four different femora that were scanned under three conditions: (1) in situ within the cadaver body, (2) in a water basin and (3) in the body model. The BMD of the three scanning protocols were compared at two locations: proximally, in the trabecular bone of the femoral head, and in the cortical bone of the femoral shaft. Proximally, no significant differences in BMD were found between the in situ scans and the scans in the body model, whereas the densities from the water basin scans were on average 10.8% lower than in situ. In the femoral shaft the differences between the three scanning protocols were insignificant. In conclusion, the body model better approached the in situ situation than a water basin. Future studies can use this body model to mimic patient situations and to develop protocols to improve the performance of the FE-models in actual patients. (note)
Kinematic simulation of human gait with a multi-rigid-body foot model
Institute of Scientific and Technical Information of China (English)
YANG Yan; HU Xiaochun; LI Xiaopeng
2012-01-01
The paper builds a multi-rigid-body model of human with a 4-rigid-body foot in the 3D CAD software Solidworks, based on human anatomy. By controlling the rotation of the ankle and major joints of human body while walking, the Kinematic simulation was performed in the dynamics simulation software ADAMS. The paper analyzes the simulate results and points out deficiencies in the current work and the direction of research efforts in future.
ECO-BIOLOGICAL SYSTEM MODELING
Directory of Open Access Journals (Sweden)
T. I. Burak
2015-01-01
Full Text Available The methodology for computer modeling of complex eco-biological models is presented in this paper. It is based on system approach of J. Forrester. Developed methodology is universal for complex ecological and biological systems. Modeling algorithm considers specialties of eco-biological systems and shows adequate and accurate results in practice.
Rigid body dynamics modeling, experimental characterization, and performance analysis of a howitzer
Institute of Scientific and Technical Information of China (English)
Nachiketa TIWARI; Mukund PATIL; Ravi SHANKAR; Abhishek SARASWAT; Rituraj DWIVEDI
2016-01-01
A large caliber howitzer is a complex and cumbersome assembly. Understanding its dynamics and performance attributes’ sensitivity to changes in its design parameters can be a very time-consuming and expensive exercise, as such an effort requires highly sophisticated test rigs and platforms. However, the need of such an understanding is crucially important for system designers, users, and evaluators. Some of the key performance attributes of such a system are its vertical jump, forward motion, recoil displacement, and force transmitted to ground through tires and trail after the gun has been fired. In this work, we have developed a rigid body dynamics model for a representative howitzer system, and used relatively simple experimental procedures to estimate its principal design parameters. Such procedures can help in obviating the need of expensive experimental rigs, especially in early stages of the design cycle. These parameters were subsequently incorporated into our simulation model, which was then used to predict gun performance. Finally, we conducted several sensitivity studies to understand the influence of changes in various design parameters on system performance. Their results provide useful insights in our understanding of the functioning of the overall system.
Rigid body dynamics modeling, experimental characterization, and performance analysis of a howitzer
Directory of Open Access Journals (Sweden)
Nachiketa Tiwari
2016-12-01
Full Text Available A large caliber howitzer is a complex and cumbersome assembly. Understanding its dynamics and performance attributes' sensitivity to changes in its design parameters can be a very time-consuming and expensive exercise, as such an effort requires highly sophisticated test rigs and platforms. However, the need of such an understanding is crucially important for system designers, users, and evaluators. Some of the key performance attributes of such a system are its vertical jump, forward motion, recoil displacement, and force transmitted to ground through tires and trail after the gun has been fired. In this work, we have developed a rigid body dynamics model for a representative howitzer system, and used relatively simple experimental procedures to estimate its principal design parameters. Such procedures can help in obviating the need of expensive experimental rigs, especially in early stages of the design cycle. These parameters were subsequently incorporated into our simulation model, which was then used to predict gun performance. Finally, we conducted several sensitivity studies to understand the influence of changes in various design parameters on system performance. Their results provide useful insights in our understanding of the functioning of the overall system.
75 FR 33166 - Extension of Expiration Dates for Several Body System Listings
2010-06-11
...: Cardiovascular System, Endocrine System, Growth Impairment, Hematological Disorders, Musculoskeletal System, Mental Disorders, Neurological, and Respiratory System. We are making no other revisions to these body...); Hematological Disorders (7.00 and 107.00); Endocrine System (9.00 and 109.00); Neurological (11.00 and...
Activity of processes on the visible surfaces of Solar System bodies
Vidmachenko, A. P.
2016-10-01
We consider the physical processes on the surfaces of Solar System bodies, which lead to visible changes in their reflective characteristics. It is shown that each body in the Solar system has a set of chemical elements and their compounds, converting of which indicates significant activity in such a significant temperature change range from 700 K (for Mercury) to 30 K for Pluto. That is, all objects in the Solar system show a significant activity. However, they are very individual for the list and the type of the processes that take place on each body in the Solar system.
A kinematic model to estimate effective dose of radioactive substances in a human body
Sasaki, S.; Yamada, T.
2013-05-01
The great earthquake occurred in the north-east area in Japan in March 11, 2011. Facility system to control Fukushima Daiichi nuclear power station was completely destroyed by the following giant tsunami. From the damaged reactor containment vessels, an amount of radioactive substances had leaked and diffused in the vicinity of this station. Radiological internal exposure became a serious social issue both in Japan and all over the world. The present study provides an easily understandable, kinematic-based model to estimate the effective dose of radioactive substances in a human body by simplifying the complicated mechanism of metabolism. International Commission on Radiological Protection (ICRP) has developed a sophisticated model, which is well-known as a standard method to calculate the effective dose for radiological protection. However, owing to that ICRP method is fine, it is rather difficult for non-professional people of radiology to gasp the whole images of the movement and the influences of radioactive substances in a human body. Therefore, in the present paper we propose a newly-derived and easily-understandable model to estimate the effective dose. The present method is very similar with the traditional and conventional tank model in hydrology. Ingestion flux of radioactive substances corresponds to rain intensity and the storage of radioactive substances to the water storage in a basin in runoff analysis. The key of the present method is to estimate the energy radiated in the radioactive nuclear disintegration of an atom by using classical theory of β decay and special relativity for various kinds of radioactive atoms. The parameters used in this model are only physical half-time and biological half-time, and there are no operational parameters or coefficients to adjust our theoretical runoff to ICRP. Figure shows the time-varying effective dose with ingestion duration, and we can confirm the validity of our model. The time-varying effective dose with
N-Body Simulation of the Formation of the Earth-Moon System from a Single Giant Impact
Eiland, Justin C; Hokr, Brett H; Highland, Justin L; Wyatt, Bryant M
2013-01-01
The giant impact hypothesis is the dominant theory of how the Earth-Moon system was formed. Models have been created that can produce a disk of debris with the proper mass and composition to create our Moon. Models have also been created which start with a disk of debris that eventually coalesces into a Moon. To date, no model has been created that produces a stable Earth-Moon system in a single simulation. Here we combine two recently published ideas in this field, along with a new gravity-centered model, and generate such a simulation. In addition, we show how the method can produce a heterogeneous, iron-deficient Moon made of mantle material from both colliding bodies, and a resultant Earth whose equatorial plane is significantly tilted off the ecliptic plane. The accuracy of the simulation adds credence to the theory that our Moon was born from the violent union of two heavenly bodies.
Institute of Scientific and Technical Information of China (English)
SUYajuan; WEIShaojun
2005-01-01
Technique of energy minimization by combining Dynamic voltage scheduling (DVS) and Adaptive body biasing voltage (ABB) method for distributed realtime system at design level is proposed. First, a simplified energy optimizing model is illustrated where the supply voltage or body biasing voltage is kept as constant according to each separated frequency region, thus calculation of exceeding equation is avoided. Divergence of simplified and analytic model within 5% indicates the accuracy of this model. Based on it, the proposed approach named LEVVS (Low energy supply voltage and body biasing voltage scheduling algorithm) explores space of minimizing energy consumption by finding optimal trade-off between dynamic and static energy. The corresponding optimal supply voltage and body biasing voltage are determined by an iterative method in which the supply voltage and body biasing voltage of tasks are adjusted according to the value of energy latency differential coefficient of each task and slack time distribution of the system. Experiments show that using LEVVS approach, 51% more average energy reduction can be obtained than employing DVS method alone. Furthermore the effects of switch capacitance and global slack on the energy saving efficiency of LEVVS are investigated. The smaller the global slack or average switch capacitance is, the more the energy saving of LEVVS compared with DVS is.
a Six-Link Kinematic Chain Model of Human Body Using Kane's Method
Rambely, A. S.; Fazrolrozi
A biomechanics model of six-link kinematic chain of human body is developed by using Kane's method. The kinematic data comprise of six segments; foot, calf, thigh, trunk, upper arm and forearm, are obtained through data collection of walking, running and jumping using the Vicon Nexus system. The motion capture system uses 12 Vicon MX-3+ cameras and 12 Vicon MX-F40 cameras, two DV (50 Hz) cameras and a force plate (100 Hz). Inverse dynamics approach is used to obtain the unknown value of torques produced by joint segments during walking, running and jumping activities. The results show that the largest value of torques produced occurs at the foot segment.
Validity and Repeatability of the Sizestream 3D Scanner and Poikos Modeling System
Vonk, T.E.; Daanen, H.A.M.
2015-01-01
Three-dimensional (3D) body scanning becomes increasingly important in the medical, ergonomical and apparel industry. The SizeStream 3D body scanner is a 3D body scanner in the shape of a fitting room that can generate a 3D copy of the human body in a few seconds. The Poikos modeling system generate
Investigation of human body potential measured by a non-contact measuring system.
Ichikawa, Norimitsu
2016-12-07
A human body is occasionally electrified in a room. This charged object will be a source of electrostatic accidents, including the malfunction of electronic equipment. Hence, prevention of these accidents is required. Accidents occasionally occur, even though antistatic clothes and shoes are used. One of the causes for these accidents is that there is a lack of the preventive measures. This situation occurs when using, for example, unconductive wax. In this study, human body potential (voltage) is measured using a non-contact measuring system. An investigation of the human body's voltage when using this system is conducted. The result demonstrates that the voltage of a human body wearing antistatic clothes and shoes or light clothes and slippers exceeds a malfunctioning voltage of a microelectronics device when the body walks on floors. Thus, accidents may occur even if a human body wearing the antistatic clothes walks on flooring. These results will be useful in estimating determination whether electrostatic accidents occur or not.
Generalized Predictive Control of Dynamic Systems with Rigid-Body Modes
Kvaternik, Raymond G.
2013-01-01
Numerical simulations to assess the effectiveness of Generalized Predictive Control (GPC) for active control of dynamic systems having rigid-body modes are presented. GPC is a linear, time-invariant, multi-input/multi-output predictive control method that uses an ARX model to characterize the system and to design the controller. Although the method can accommodate both embedded (implicit) and explicit feedforward paths for incorporation of disturbance effects, only the case of embedded feedforward in which the disturbances are assumed to be unknown is considered here. Results from numerical simulations using mathematical models of both a free-free three-degree-of-freedom mass-spring-dashpot system and the XV-15 tiltrotor research aircraft are presented. In regulation mode operation, which calls for zero system response in the presence of disturbances, the simulations showed reductions of nearly 100%. In tracking mode operations, where the system is commanded to follow a specified path, the GPC controllers produced the desired responses, even in the presence of disturbances.
Raque-Bogdan, Trisha L; Piontkowski, Sarah; Hui, Kayi; Ziemer, Kathryn Schaefer; Garriott, Patton O
2016-12-01
Body appreciation has been found to be linked to interpersonal and intrapersonal factors, with attachment styles and self-compassion separately identified as important correlates. The present study examined these variables together in a model, and we hypothesized that maternal attachment anxiety was related to peer and romantic attachment anxiety, which, in turn, was associated with self-compassion and body appreciation. Using structural equation modeling, this cross-sectional study with a sample of 1306 incoming first year college women found that the proposed model explained 40% of the variance in body appreciation. Results further revealed that peer and romantic attachment anxiety mediated the relationships between maternal attachment anxiety and self-compassion, and that self-compassion mediated the associations between peer and romantic attachment anxiety and body appreciation. Self-compassion appears to hold a central role in explaining the relation between attachment anxiety and body appreciation.
Experimental studies of few-body systems at MAMI
Distler, M. O.
2011-09-01
Few-body experiments at the Mainz Microtron were focused on a number of selected topics. Double-polarization experiments to determine the neutron electric form factor Gen have been performed using both deuterium and polarized helium-3 targets. The structure of 3He has been studied in the reactions 3H e⃗ e( e⃗ e, e' n) and 3H e⃗ e( e⃗ e, e' p) with large (transversal) missing momenta and in quasi-elastic electron scattering. Electromagnetically induced two-nucleon knockout has been investigated in order to study the role of correlated nucleon-nucleon motion in the nucleus. Measurements of the ( e, e' pn) reaction on 3He and 16O were performed for the first time. A triple-polarization experiment of type 3H e⃗ e( e⃗ e, e'e⃗ p⃗) d has been performed, where, in addition, the spin of the knocked out proton is analyzed. This measurement provides information on the spin-dependent momentum distribution of proton-deuteron clusters in the 3He nucleus. Hence, by tagging the outgoing deuteron spin-polarized 3He might also serve as an effective polarized proton target for electron scattering experiments. Moreover, in inclusive 3,4He( e, e') measurements at low momentum transfer, the effect of 3-body-forces has been studied.
Establishment of Early Endpoints in Mouse Total-Body Irradiation Model
Gulani, Jatinder; King, Gregory; Hieber, Kevin; Chappell, Mark; Ossetrova, Natalia
2016-01-01
Acute radiation sickness (ARS) following exposure to ionizing irradiation is characterized by radiation-induced multiorgan dysfunction/failure that refers to progressive dysfunction of two or more organ systems, the etiological agent being radiation damage to cells and tissues over time. Radiation sensitivity data on humans and animals has made it possible to describe the signs associated with ARS. A mouse model of total-body irradiation (TBI) has previously been developed that represents the likely scenario of exposure in the human population. Herein, we present the Mouse Intervention Scoring System (MISS) developed at the Veterinary Sciences Department (VSD) of the Armed Forces Radiobiology Research Institute (AFRRI) to identify moribund mice and decrease the numbers of mice found dead, which is therefore a more humane refinement to death as the endpoint. Survival rates were compared to changes in body weights and temperatures in the mouse (CD2F1 male) TBI model (6–14 Gy, 60Co γ-rays at 0.6 Gy min-1), which informed improvements to the Scoring System. Individual tracking of animals via implanted microchips allowed for assessment of criteria based on individuals rather than by group averages. From a total of 132 mice (92 irradiated), 51 mice were euthanized versus only four mice that were found dead (7% of non-survivors). In this case, all four mice were found dead after overnight periods between observations. Weight loss alone was indicative of imminent succumbing to radiation injury, however mice did not always become moribund within 24 hours while having weight loss >30%. Only one survivor had a weight loss of greater than 30%. Temperature significantly dropped only 2–4 days before death/euthanasia in 10 and 14 Gy animals. The score system demonstrates a significant refinement as compared to using subjective assessment of morbidity or death as the endpoint for these survival studies. PMID:27579862
Establishment of Early Endpoints in Mouse Total-Body Irradiation Model.
Koch, Amory; Gulani, Jatinder; King, Gregory; Hieber, Kevin; Chappell, Mark; Ossetrova, Natalia
2016-01-01
Acute radiation sickness (ARS) following exposure to ionizing irradiation is characterized by radiation-induced multiorgan dysfunction/failure that refers to progressive dysfunction of two or more organ systems, the etiological agent being radiation damage to cells and tissues over time. Radiation sensitivity data on humans and animals has made it possible to describe the signs associated with ARS. A mouse model of total-body irradiation (TBI) has previously been developed that represents the likely scenario of exposure in the human population. Herein, we present the Mouse Intervention Scoring System (MISS) developed at the Veterinary Sciences Department (VSD) of the Armed Forces Radiobiology Research Institute (AFRRI) to identify moribund mice and decrease the numbers of mice found dead, which is therefore a more humane refinement to death as the endpoint. Survival rates were compared to changes in body weights and temperatures in the mouse (CD2F1 male) TBI model (6-14 Gy, 60Co γ-rays at 0.6 Gy min-1), which informed improvements to the Scoring System. Individual tracking of animals via implanted microchips allowed for assessment of criteria based on individuals rather than by group averages. From a total of 132 mice (92 irradiated), 51 mice were euthanized versus only four mice that were found dead (7% of non-survivors). In this case, all four mice were found dead after overnight periods between observations. Weight loss alone was indicative of imminent succumbing to radiation injury, however mice did not always become moribund within 24 hours while having weight loss >30%. Only one survivor had a weight loss of greater than 30%. Temperature significantly dropped only 2-4 days before death/euthanasia in 10 and 14 Gy animals. The score system demonstrates a significant refinement as compared to using subjective assessment of morbidity or death as the endpoint for these survival studies.
Image method for induced surface charge from many-body system of dielectric spheres
Qin, Jian; de Pablo, Juan J.; Freed, Karl F.
2016-09-01
Charged dielectric spheres embedded in a dielectric medium provide the simplest model for many-body systems of polarizable ions and charged colloidal particles. We provide a multiple scattering formulation for the total electrostatic energy for such systems and demonstrate that the polarization energy can be rapidly evaluated by an image method that generalizes the image methods for conducting spheres. Individual contributions to the total electrostatic energy are ordered according to the number of polarized surfaces involved, and each additional surface polarization reduces the energy by a factor of (a/R)3ɛ, where a is the sphere radius, R the average inter-sphere separation, and ɛ the relevant dielectric mismatch at the interface. Explicit expressions are provided for both the energy and the forces acting on individual spheres, which can be readily implemented in Monte Carlo and molecular dynamics simulations of polarizable charged spheres, thereby avoiding costly computational techniques that introduce a surface charge distribution that requires numerical solution.
Simulation model of SAR remote sensing of turbulent wake of semi-elliptical submerged body
Institute of Scientific and Technical Information of China (English)
无
2005-01-01
In terms of the 2-dimensional hydrodynamic simplified model of a semi-elliptical submerged body moving horizontally at high speed,by using the full-spectrum model of SAR(synthetic aperture radar) remote sensing and taking the effect of oceanic interior turbulence on surface gravity capillary waves into account, applying the k-ε model of turbulence with internal wave mixing, and adopting the Nasmyth spectrum of oceanic turbulence, the 2-dimensional simulation model of SAR remote sensing of this semi-elliptical submerged body is built up. Simulation by using this model at X band and C band is made in the northeastern South China Sea (21°00'N,119°00'E). Satisfactory results of the delay time and delay distance of turbulent surface wake of this semi-elliptical submerged body, as well as the minimum submerged depth at which this submerged body which cannot be discovered by SAR, are obtained through simulation.
Spectrum of quantum transfer matrices via classical many-body systems
Energy Technology Data Exchange (ETDEWEB)
Gorsky, A. [ITEP,Bolshaya Cheremushkinskaya str. 25, 117218, Moscow (Russian Federation); MIPT,Inststitutskii per. 9, 141700, Dolgoprudny, Moscow region (Russian Federation); Zabrodin, A. [ITEP,Bolshaya Cheremushkinskaya str. 25, 117218, Moscow (Russian Federation); MIPT,Inststitutskii per. 9, 141700, Dolgoprudny, Moscow region (Russian Federation); Institute of Biochemical Physics,Kosygina str. 4, 119991, Moscow (Russian Federation); National Research University Higher School of Economics,Myasnitskaya str. 20, 101000, Moscow (Russian Federation); Zotov, A. [ITEP,Bolshaya Cheremushkinskaya str. 25, 117218, Moscow (Russian Federation); MIPT,Inststitutskii per. 9, 141700, Dolgoprudny, Moscow region (Russian Federation); Steklov Mathematical Institute, RAS,Gubkina str. 8, 119991, Moscow (Russian Federation)
2014-01-15
In this paper we clarify the relationship between inhomogeneous quantum spin chains and classical integrable many-body systems. It provides an alternative (to the nested Bethe ansatz) method for computation of spectra of the spin chains. Namely, the spectrum of the quantum transfer matrix for the inhomogeneous gl{sub n}-invariant XXX spin chain on N sites with twisted boundary conditions can be found in terms of velocities of particles in the rational N-body Ruijsenaars-Schneider model. The possible values of the velocities are to be found from intersection points of two Lagrangian submanifolds in the phase space of the classical model. One of them is the Lagrangian hyperplane corresponding to fixed coordinates of all N particles and the other one is an N-dimensional Lagrangian submanifold obtained by fixing levels of N classical Hamiltonians in involution. The latter are determined by eigenvalues of the twist matrix. To support this picture, we give a direct proof that the eigenvalues of the Lax matrix for the classical Ruijsenaars-Schneider model, where velocities of particles are substituted by eigenvalues of the spin chain Hamiltonians, calculated through the Bethe equations, coincide with eigenvalues of the twist matrix, with certain multiplicities. We also prove a similar statement for the gl{sub n} Gaudin model with N marked points (on the quantum side) and the Calogero-Moser system with N particles (on the classical side). The realization of the results obtained in terms of branes and supersymmetric gauge theories is also discussed.
Testing lowered isothermal models with direct N-body simulations of globular clusters
Zocchi, Alice; Hénault-Brunet, Vincent; Varri, Anna Lisa
2016-01-01
Several self-consistent models have been proposed, aiming at describing the phase space distribution of stars in globular clusters. This study explores the ability of the recently proposed LIMEPY models (Gieles & Zocchi) to reproduce the dynamical properties of direct N-body models of a cluster in a tidal field, during its entire evolution. These dynamical models include prescriptions for the truncation and the degree of radially-biased anisotropy contained in the system, allowing us to explore the interplay between the role of anisotropy and tides in various stages of the life of star clusters. We show that the amount of anisotropy in an initially tidally underfilling cluster increases in the pre-collapse phase, and then decreases with time, due to the effect of the external tidal field on its spatial truncation. This is reflected in the correspondent model parameters, and the best-fit models reproduce the main properties of the cluster at all stages of its evolution, except for the phases immediately pr...
Validation of a heat conduction model for finite domain, non-uniformly heated, laminate bodies
Desgrosseilliers, Louis; Kabbara, Moe; Groulx, Dominic; White, Mary Anne
2016-07-01
Infrared thermographic validation is shown for a closed-form analytical heat conduction model for non-uniformly heated, laminate bodies with an insulated domain boundary. Experiments were conducted by applying power to rectangular electric heaters and cooled by natural convection in air, but also apply to constant-temperature heat sources and forced convection. The model accurately represents two-dimensional laminate heat conduction behaviour giving rise to heat spreading using one-dimensional equations for the temperature distributions and heat transfer rates under steady-state and pseudo-steady-state conditions. Validation of the model with an insulated boundary (complementing previous studies with an infinite boundary) provides useful predictions of heat spreading performance and simplified temperature uniformity calculations (useful in log-mean temperature difference style heat exchanger calculations) for real laminate systems such as found in electronics heat sinks, multi-ply stovetop cookware and interface materials for supercooled salt hydrates. Computational determinations of implicit insulated boundary condition locations in measured data, required to assess model equation validation, were also demonstrated. Excellent goodness of fit was observed (both root-mean-square error and R 2 values), in all cases except when the uncertainty of low temperatures measured via infrared thermography hindered the statistical significance of the model fit. The experimental validation in all other cases supports use of the model equations in design calculations and heat exchange simulations.
Hase, Kazunori; Obinata, Goro
It is essential for the biomechanical study of human walking motion to consider not only in vivo mechanical load and energy efficiency but also aspects of motor control such as walking stability. In this study, walking stability was investigated using a three-dimensional entire-body neuro-musculo-skeletal model in the computer simulation. In the computational experiments, imaginary constraints, such as no muscular system, were set in the neuro-musculo-skeletal model to investigate their influence on walking stability. The neuronal parameters were adjusted using numerical search techniques in order to adapt walking patterns to constraints on the neuro-musculo-skeletal system. Simulation results revealed that the model of the normal neuro-musculo-skeletal system yielded a higher stability than the imaginary models. Unstable walking by a model with a time delay in the neuronal system suggested significant unknown mechanisms which stabilized walking patterns that have been neglected in previous studies.
Body posture recognition and turning recording system for the care of bed bound patients.
Hsiao, Rong-Shue; Mi, Zhenqiang; Yang, Bo-Ru; Kau, Lih-Jen; Bitew, Mekuanint Agegnehu; Li, Tzu-Yu
2015-01-01
This paper proposes body posture recognition and turning recording system for assisting the care of bed bound patients in nursing homes. The system continuously detects the patient's body posture and records the length of time for each body posture. If the patient remains in the same body posture long enough to develop pressure ulcers, the system notifies caregivers to change the patient's body posture. The objective of recording is to provide the log of body turning for querying of patients' family members. In order to accurately detect patient's body posture, we developed a novel pressure sensing pad which contains force sensing resistor sensors. Based on the proposed pressure sensing pad, we developed a bed posture recognition module which includes a bed posture recognition algorithm. The algorithm is based on fuzzy theory. The body posture recognition algorithm can detect the patient's bed posture whether it is right lateral decubitus, left lateral decubitus, or supine. The detected information of patient's body posture can be then transmitted to the server of healthcare center by the communication module to perform the functions of recording and notification. Experimental results showed that the average posture recognition accuracy for our proposed module is 92%.
Editorial: Focus on Dynamics and Thermalization in Isolated Quantum Many-Body Systems
Cazalilla, M. A.; Rigol, M.
2010-05-01
understand many-body quantum systems. This focus issue of New Journal Physics brings together both experimentalists and theoreticians working on these problems to provide a comprehensive picture of the state of the field. Focus on Dynamics and Thermalization in Isolated Quantum Many-Body Systems Contents Spin squeezing of high-spin, spatially extended quantum fields Jay D Sau, Sabrina R Leslie, Marvin L Cohen and Dan M Stamper-Kurn Thermodynamic entropy of a many-body energy eigenstate J M Deutsch Ground states and dynamics of population-imbalanced Fermi condensates in one dimension Masaki Tezuka and Masahito Ueda Relaxation dynamics in the gapped XXZ spin-1/2 chain Jorn Mossel and Jean-Sébastien Caux Canonical thermalization Peter Reimann Minimally entangled typical thermal state algorithms E M Stoudenmire and Steven R White Manipulation of the dynamics of many-body systems via quantum control methods Julie Dinerman and Lea F Santos Multimode analysis of non-classical correlations in double-well Bose-Einstein condensates Andrew J Ferris and Matthew J Davis Thermalization in a quasi-one-dimensional ultracold bosonic gas I E Mazets and J Schmiedmayer Two simple systems with cold atoms: quantum chaos tests and non-equilibrium dynamics Cavan Stone, Yassine Ait El Aoud, Vladimir A Yurovsky and Maxim Olshanii On the speed of fluctuations around thermodynamic equilibrium Noah Linden, Sandu Popescu, Anthony J Short and Andreas Winter A quantum central limit theorem for non-equilibrium systems: exact local relaxation of correlated states M Cramer and J Eisert Quantum quench dynamics of the sine-Gordon model in some solvable limits A Iucci and M A Cazalilla Nonequilibrium quantum dynamics of atomic dark solitons A D Martin and J Ruostekoski Quantum quenches in the anisotropic spin-1⁄2 Heisenberg chain: different approaches to many-body dynamics far from equilibrium Peter Barmettler, Matthias Punk, Vladimir Gritsev, Eugene Demler and Ehud Altman Crossover from adiabatic to sudden
A new cantilever beam-rigid-body MEMS gyroscope: mathematical model and linear dynamics
Lajimi, Seyed Amir Mousavi; Abdel-Rahman, Eihab
2014-01-01
A new microbeam-rigid-body gyroscope is introduced and its static and dynamic behaviours are studied. The main structure includes a microbeam and an eccentric end-rigid-body influencing the dynamic and static characteristics of the sensor. The sensitivity of the device and the effect of system parameters on the microsystem's response are investigated.
Assessment of physical activity of the human body considering the thermodynamic system.
Hochstein, Stefan; Rauschenberger, Philipp; Weigand, Bernhard; Siebert, Tobias; Schmitt, Syn; Schlicht, Wolfgang; Převorovská, Světlana; Maršík, František
2016-01-01
Correctly dosed physical activity is the basis of a vital and healthy life, but the measurement of physical activity is certainly rather empirical resulting in limited individual and custom activity recommendations. Certainly, very accurate three-dimensional models of the cardiovascular system exist, however, requiring the numeric solution of the Navier-Stokes equations of the flow in blood vessels. These models are suitable for the research of cardiac diseases, but computationally very expensive. Direct measurements are expensive and often not applicable outside laboratories. This paper offers a new approach to assess physical activity using thermodynamical systems and its leading quantity of entropy production which is a compromise between computation time and precise prediction of pressure, volume, and flow variables in blood vessels. Based on a simplified (one-dimensional) model of the cardiovascular system of the human body, we develop and evaluate a setup calculating entropy production of the heart to determine the intensity of human physical activity in a more precise way than previous parameters, e.g. frequently used energy considerations. The knowledge resulting from the precise real-time physical activity provides the basis for an intelligent human-technology interaction allowing to steadily adjust the degree of physical activity according to the actual individual performance level and thus to improve training and activity recommendations.
Kim, Minsoo; Kim, Yejin; Kim, Hyosoo; Piao, Wenhua; Kim, Changwon
2016-06-01
An operator decision support system (ODSS) is proposed to support operators of wastewater treatment plants (WWTPs) in making appropriate decisions. This system accounts for water quality (WQ) variations in WWTP influent and effluent and in the receiving water body (RWB). The proposed system is comprised of two diagnosis modules, three prediction modules, and a scenario-based supporting module (SSM). In the diagnosis modules, the WQs of the influent and effluent WWTP and of the RWB are assessed via multivariate analysis. Three prediction modules based on the k-nearest neighbors (k-NN) method, activated sludge model no. 2d (ASM2d) model, and QUAL2E model are used to forecast WQs for 3 days in advance. To compare various operating alternatives, SSM is applied to test various predetermined operating conditions in terms of overall oxygen transfer coefficient (Kla), waste sludge flow rate (Qw), return sludge flow rate (Qr), and internal recycle flow rate (Qir). In the case of unacceptable total phosphorus (TP), SSM provides appropriate information for the chemical treatment. The constructed ODSS was tested using data collected from Geumho River, which was the RWB, and S WWTP in Daegu City, South Korea. The results demonstrate the capability of the proposed ODSS to provide WWTP operators with more objective qualitative and quantitative assessments of WWTP and RWB WQs. Moreover, the current study shows that ODSS, using data collected from the study area, can be used to identify operational alternatives through SSM at an integrated urban wastewater management level.
Analytical Solution of Relativistic Few-Body Bound Systems with a Generalized Yukawa Potential
Aslanzadeh, M.; Rajabi, A. A.
2016-03-01
We have investigated in this paper the few-body bound systems in a simple semi-relativistic scheme. For this aim, we introduced a spin independent relativistic description for a few-identical body system by presenting the analytical solution of few-particle Klein-Gordon equation. Performing calculations in D-dimensional configuration on the basis of the hypercentral approach, we reduced the few-body Klein-Gordon equation to a Schrödinger-like form. This equation is solved by using the Nikiforov-Uvarov method, through which the energy equations and eigenfunctions for a few-body bound system are obtained. We used the spin- and isospin-independent generalized Yukawa potential in our calculations, and the dependence of the few-body binding energies on the potential parameters has been investigated.
Flexible quality of service model for wireless body area sensor networks.
Liao, Yangzhe; Leeson, Mark S; Higgins, Matthew D
2016-03-01
Wireless body area sensor networks (WBASNs) are becoming an increasingly significant breakthrough technology for smart healthcare systems, enabling improved clinical decision-making in daily medical care. Recently, radio frequency ultra-wideband technology has developed substantially for physiological signal monitoring due to its advantages such as low-power consumption, high transmission data rate, and miniature antenna size. Applications of future ubiquitous healthcare systems offer the prospect of collecting human vital signs, early detection of abnormal medical conditions, real-time healthcare data transmission and remote telemedicine support. However, due to the technical constraints of sensor batteries, the supply of power is a major bottleneck for healthcare system design. Moreover, medium access control (MAC) needs to support reliable transmission links that allow sensors to transmit data safely and stably. In this Letter, the authors provide a flexible quality of service model for ad hoc networks that can support fast data transmission, adaptive schedule MAC control, and energy efficient ubiquitous WBASN networks. Results show that the proposed multi-hop communication ad hoc network model can balance information packet collisions and power consumption. Additionally, wireless communications link in WBASNs can effectively overcome multi-user interference and offer high transmission data rates for healthcare systems.
Mathematical System Theory and System Modeling
1980-01-01
Choosing models related effectively to the questions to be addressed is a central issue in the craft of systems analysis. Since the mathematical description the analyst chooses constrains the types of issues he candeal with, it is important for these models to be selected so as to yield limitations that are acceptable in view of the questions the systems analysis seeks to answer. In this paper, the author gives an overview of the central issues affecting the question of model choice. To ...
Simuluating quantum many-body systems subject to measurements
DEFF Research Database (Denmark)
Gammelmark, Søren
is found. The technique is exemplified by numerical simulations of the antiferromagnetic Heisenberg spin-chain model subject to various instances of the measurement model. In particular, we focus on local measurements with small support and nonlocal measurements, which induce long-range correlations....
Simulating quantum many-body systems subject to measurements
DEFF Research Database (Denmark)
Gammelmark, Søren
is found. The technique is exemplified by numerical simulations of the antiferromagnetic Heisenberg spin-chain model subject to various instances of the measurement model. In particular, we focus on local measurements with small support and nonlocal measurements, which induce long-range correlations....
Two, three, many body systems involving mesons. Multimeson condensates
Oset, E; Dote, A; Hyodo, T; Khemchandani, P K; Liang, W H; Torres, A Martinez; Oka, M; Roca, L; Uchino, T; Xiao, C W
2015-01-01
In this talk we review results from studies with unconventional many hadron systems containing mesons: systems with two mesons and one baryon, three mesons, some novel systems with two baryons and one meson, and finally systems with many vector mesons, up to six, with their spins aligned forming states of increasing spin. We show that in many cases one has experimental counterparts for the states found, while in some other cases they remain as predictions, which we suggest to be searched in BESIII, Belle, LHCb, FAIR and other facilities.
Lee, Greg; Polidan, Ronald; Ross, Floyd; Sokol, Daniel; Warwick, Steve
2015-11-01
Northrop Grumman and L’Garde have continued the development of a hypersonic entry, semi-buoyant, maneuverable platform capable of performing long-duration (months to a year) in situ and remote measurements at any solar system body that possesses an atmosphere.The Lifting Entry & Atmospheric Flight (LEAF) family of vehicles achieves this capability by using a semi-buoyant, ultra-low ballistic coefficient vehicle whose lifting entry allows it to enter the atmosphere without an aeroshell. The mass savings realized by eliminating the heavy aeroshell allows significantly more payload to be accommodated by the platform for additional science collection and return.In this presentation, we discuss the application of the LEAF system at various solar system bodies: Venus, Titan, Mars, and Earth. We present the key differences in platform design as well as operational differences required by the various target environments. The Venus implementation includes propulsive capability to reach higher altitudes during the day and achieves full buoyancy in the mid-cloud layer of Venus’ atmosphere at night.Titan also offers an attractive operating environment, allowing LEAF designs that can target low or medium altitude operations, also with propulsive capabilities to roam within each altitude regime. The Mars version is a glider that descends gradually, allowing targeted delivery of payloads to the surface or high resolution surface imaging. Finally, an Earth version could remain in orbit in a stowed state until activated, allowing rapid response type deployments to any region of the globe.
Impact of Wireless Channel Model on 802.15.6 Standard Performance for Wireless Body Sensor Networks
Directory of Open Access Journals (Sweden)
Maryam El azhari
2016-05-01
Full Text Available Wireless Body Sensor Network (WBAN is a set of wearable and implantable devices capable of measuring physiological parameters and monitoring patient with chronic disease where early diagnosis is highly demanded. Several models introduced the general characterization of WBAN devices path loss considering possible shadowing due to obstruction of the signal (by the human body or any other obstacles as well as the different postures of the human body. This paper aims at reporting an overview of WBSNs technologies, particular applications, system architecture and channel modeling. Emphasis is given to the IEEE 802.15.6 standard which enables the development of WBAN for medical and non-medical applications. The standard's performance within a time based variation and log-distance path loss is presented based on various simulations.
Two body scattering length of Yukawa model on a lattice
De Soto, F; Roiesnel, C; Boucaud, P; Leroy, J P; Pène, O; Boucaud, Ph.
2007-01-01
The extraction of scattering parameters from Euclidean simulations of a Yukawa model in a finite volume with periodic boundary conditions is analyzed both in non relativistic quantum mechanics and in quantum field theory.
Mathematical modeling of spinning elastic bodies for modal analysis.
Likins, P. W.; Barbera, F. J.; Baddeley, V.
1973-01-01
The problem of modal analysis of an elastic appendage on a rotating base is examined to establish the relative advantages of various mathematical models of elastic structures and to extract general inferences concerning the magnitude and character of the influence of spin on the natural frequencies and mode shapes of rotating structures. In realization of the first objective, it is concluded that except for a small class of very special cases the elastic continuum model is devoid of useful results, while for constant nominal spin rate the distributed-mass finite-element model is quite generally tractable, since in the latter case the governing equations are always linear, constant-coefficient, ordinary differential equations. Although with both of these alternatives the details of the formulation generally obscure the essence of the problem and permit very little engineering insight to be gained without extensive computation, this difficulty is not encountered when dealing with simple concentrated mass models.
Parametric modelling and segmentation of vertebral bodies in 3D CT and MR spine images
Štern, Darko; Likar, Boštjan; Pernuš, Franjo; Vrtovec, Tomaž
2011-12-01
Accurate and objective evaluation of vertebral deformations is of significant importance in clinical diagnostics and therapy of pathological conditions affecting the spine. Although modern clinical practice is focused on three-dimensional (3D) computed tomography (CT) and magnetic resonance (MR) imaging techniques, the established methods for evaluation of vertebral deformations are limited to measuring deformations in two-dimensional (2D) x-ray images. In this paper, we propose a method for quantitative description of vertebral body deformations by efficient modelling and segmentation of vertebral bodies in 3D. The deformations are evaluated from the parameters of a 3D superquadric model, which is initialized as an elliptical cylinder and then gradually deformed by introducing transformations that yield a more detailed representation of the vertebral body shape. After modelling the vertebral body shape with 25 clinically meaningful parameters and the vertebral body pose with six rigid body parameters, the 3D model is aligned to the observed vertebral body in the 3D image. The performance of the method was evaluated on 75 vertebrae from CT and 75 vertebrae from T2-weighted MR spine images, extracted from the thoracolumbar part of normal and pathological spines. The results show that the proposed method can be used for 3D segmentation of vertebral bodies in CT and MR images, as the proposed 3D model is able to describe both normal and pathological vertebral body deformations. The method may therefore be used for initialization of whole vertebra segmentation or for quantitative measurement of vertebral body deformations.
Composite modeling method in dynamics of planar mechanical system
Institute of Scientific and Technical Information of China (English)
2008-01-01
This paper presents a composite modeling method of the forward dynamics in general planar mechanical system. In the modeling process, the system dynamic model is generated by assembling the model units which are kinematical determinate in planar mechanisms rather than the body/joint units in multi-body system. A state space formulation is employed to model both the unit and system models. The validation and feasibility of the method are illustrated by a case study of a four-bar mechanism. The advantage of this method is that the models are easier to reuse and the system is easier to reconfigure. The formulation reveals the relationship between the topology and dynamics of the planar mechanism to some extent.
Composite modeling method in dynamics of planar mechanical system
Institute of Scientific and Technical Information of China (English)
WANG Hao; LIN ZhongQin; LAI XinMin
2008-01-01
This paper presents a composite modeling method of the forward dynamics in general planar mechanical system.In the modeling process,the system dynamic model is generated by assembling the model units which are kinematical determi-nate in planar mechanisms rather than the body/joint units in multi-body system.A state space formulation is employed to model both the unit and system models.The validation and feasibility of the method are illustrated by a case study of a four-bar mechanism.The advantage of this method is that the models are easier to reuse and the system is easier to reconfigure.The formulation reveals the rela-tionship between the topology and dynamics of the planar mechanism to some extent.
Spectrum of Quantum Transfer Matrices via Classical Many-Body Systems
Gorsky, A; Zotov, A
2014-01-01
In this paper we clarify the relationship between inhomogeneous quantum spin chains and classical integrable many-body systems. It provides an alternative (to the nested Bethe ansatz) method for computation of spectra of the spin chains. Namely, the spectrum of the quantum transfer matrix for the inhomogeneous ${\\mathfrak g}{\\mathfrak l}_n$-invariant XXX spin chain on $N$ sites with twisted boundary conditions can be found in terms of velocities of particles in the rational $N$-body Ruijsenaars-Schneider model. The possible values of the velocities are to be found from intersection points of two Lagrangian submanifolds in the phase space of the classical model. One of them is the Lagrangian hyperplane corresponding to fixed coordinates of all $N$ particles and the other one is an $N$-dimensional Lagrangian submanifold obtained by fixing levels of $N$ classical Hamiltonians in involution. The latter are determined by eigenvalues of the twist matrix. To support this picture, we give a direct proof that the eige...
Equivalent dynamical complexity in a many-body quantum and collective human system
Johnson, Neil F; Zhao, Zhenyuan; Quiroga, Luis
2010-01-01
Proponents of Complexity Science believe that the huge variety of emergent phenomena observed throughout nature, are generated by relatively few microscopic mechanisms [1-7]. Skeptics however point to the lack of concrete examples in which a single mechanistic model manages to capture relevant macroscopic and microscopic properties for two or more distinct systems operating across radically different length and time scales. Here we show how a single complexity model built around cluster coalescence and fragmentation, can cross the fundamental divide between many-body quantum physics and social science. It simultaneously (i) explains a mysterious recent finding concerning quantum many-body effects in cuprate superconductors [8,9] (i.e. scale of 10^{-9}-10^{-4} meters and 10^{-12}-10^{-6} seconds), (ii) explains the apparent universality of the casualty distributions in distinct human insurgencies and terrorism [10] (i.e. scale of 10^{3}-10^{6} meters and 10^{4}-10^{8} seconds), (iii) shows consistency with var...
Ventilation and Radon Reduction System of Whole Body Counter’s Shielding Room in CIAE
Institute of Scientific and Technical Information of China (English)
WANG; Li-jiao; XIAO; Wen-hui; LU; Zheng; WEN; Fu-ping; HE; Li-hua; XIA; Yi-hua
2015-01-01
In 2015,the whole body counter of the Department of Radiation Safety was retrofitted.The whole body counter was used for monitoring radiation workers’internal exposure doses.One of the contents in this project was the retrofit of a ventilation and radon reduction system in the low
Micromechanical modelling of oil palm empty fruit bunch fibres containing silica bodies.
Omar, Farah Nadia; Hanipah, Suhaiza Hanim; Xiang, Loo Yu; Mohammed, Mohd Afandi P; Baharuddin, Azhari Samsu; Abdullah, Jaafar
2016-09-01
Experimental and numerical investigation was conducted to study the micromechanics of oil palm empty fruit bunch fibres containing silica bodies. The finite viscoelastic-plastic material model called Parallel Rheological Network model was proposed, that fitted well with cyclic and stress relaxation tensile tests of the fibres. Representative volume element and microstructure models were developed using finite element method, where the models information was obtained from microscopy and X-ray micro-tomography analyses. Simulation results showed that difference of the fibres model with silica bodies and those without ones is larger under shear than compression and tension. However, in comparison to geometrical effect (i.e. silica bodies), it is suggested that ultrastructure components of the fibres (modelled using finite viscoelastic-plastic model) is responsible for the complex mechanical behaviour of oil palm fibres. This can be due to cellulose, hemicellulose and lignin components and the interface behaviour, as reported on other lignocellulosic materials.
Spacecraft/rover hybrids for the exploration of small Solar System bodies
Pavone, M.; Castillo-Rogez, J. C.; Nesnas, I. A. D.; Hoffman, J. A.; Strange, N. J.
In this paper we present a mission architecture for the systematic and affordable in-situ exploration of small Solar System bodies (such as asteroids, comets, and Martian moons). At a general level, a mother spacecraft would deploy on the surface of a small body one, or several, spacecraft/rover hybrids, which are small (robots enclosing three mutually orthogonal flywheels and surrounded by external spikes (in particular, there is no external propulsion). By accelerating/decelerating the flywheels and by exploiting the low gravity environment, the hybrids would be capable of performing both long excursions (by hopping) and short traverses to specific locations (through a sequence of controlled “ tumbles” ). Their control would rely on synergistic operations with the mother spacecraft (where most of hybrids perception and localization functionalities would be hosted), which would make the platforms minimalistic and in turn the entire mission architecture affordable. Specifically, in the first part of the paper we present preliminary models and laboratory experiments for the hybrids, first-order estimates for critical subsystems, and a preliminary study for synergistic mission operations. In the second part, we tailor our mission architecture to the exploration of Mars' moon Phobos. The mission aims at exploring Phobos' Stickney crater, whose spectral similarities with C-type asteroids and variety of terrain properties make it a particularly interesting exploration target to address both high-priority science for the Martian system and strategic knowledge gaps for the future human exploration of Mars.
Multi-Body Analysis of the 1/5 Scale Wind Tunnel Model of the V-22 Tiltrotor
Ghiringhelli, G. L.; Masarati, P.; Mantegazza, P.; Nixon, M. W.
1999-01-01
The paper presents a multi-body analysis of the 1/5 scale wind tunnel model of the V-22 tiltrotor, the Wing and Rotor Aeroelastic Testing System (WRATS), currently tested at NASA Langley Research Center. An original multi-body formulation has been developed at the Dipartimento di Ingegneria Aerospaziale of the Politecnico di Milano, Italy. It is based on the direct writing of the equilibrium equations of independent rigid bodies, connected by kinematic constraints that result in the addition of algebraic constraint equations, and by dynamic constraints, that directly contribute to the equilibrium equations. The formulation has been extended to the simultaneous solution of interdisciplinary problems by modeling electric and hydraulic networks, for aeroservoelastic problems. The code has been tailored to the modeling of rotorcrafts while preserving a complete generality. A family of aerodynamic elements has been introduced to model high aspect aerodynamic surfaces, based on the strip theory, with quasi-steady aerodynamic coefficients, compressibility, post-stall interpolation of experimental data, dynamic stall modeling, and radial flow drag. Different models for the induced velocity of the rotor can be used, from uniform velocity to dynamic in flow. A complete dynamic and aeroelastic analysis of the model of the V-22 tiltrotor has been performed, to assess the validity of the formulation and to exploit the unique features of multi-body analysis with respect to conventional comprehensive rotorcraft codes; These are the ability to model the exact kinematics of mechanical systems, and the possibility to simulate unusual maneuvers and unusual flight conditions, that are particular to the tiltrotor, e.g. the conversion maneuver. A complete modal validation of the analytical model has been performed, to assess the ability to reproduce the correct dynamics of the system with a relatively coarse beam model of the semispan wing, pylon and rotor. Particular care has been used
The Contribution of Pre-impact Spine Posture on Human Body Model Response in Whole-body Side Impact.
Poulard, David; Subit, Damien; Donlon, John-Paul; Lessley, David J; Kim, Taewung; Park, Gwansik; Kent, Richard W
2014-11-01
The objective of the study was to analyze independently the contribution of pre-impact spine posture on impact response by subjecting a finite element human body model (HBM) to whole-body, lateral impacts. Seven postured models were created from the original HBM: one matching the standard driving posture and six matching pre-impact posture measured for each of six subjects tested in previously published experiments. The same measurements as those obtained during the experiments were calculated from the simulations, and biofidelity metrics based on signals correlation were established to compare the response of HBM to that of the cadavers. HBM responses showed good correlation with the subject response for the reaction forces, the rib strain (correlation score=0.8) and the overall kinematics. The pre-impact posture was found to greatly alter the reaction forces, deflections and the strain time histories mainly in terms of time delay. By modifying only the posture of HBM, the variability in the impact response was found to be equivalent to that observed in the experiments performed with cadavers with different anthropometries. The patterns observed in the responses of the postured HBM indicate that the inclination of the spine in the frontal plane plays a major role. The postured HBM sustained from 2 to 5 bone fractures, including the scapula in some cases, confirming that the pre-impact posture influences the injury outcome predicted by the simulation.
An attempt to model the human body as a communication channel.
Wegmueller, Marc Simon; Kuhn, Andreas; Froehlich, Juerg; Oberle, Michael; Felber, Norbert; Kuster, Niels; Fichtner, Wolfgang
2007-10-01
Using the human body as a transmission medium for electrical signals offers novel data communication in biomedical monitoring systems. In this paper, galvanic coupling is presented as a promising approach for wireless intra-body communication between on-body sensors. The human body is characterized as a transmission medium for electrical current by means of numerical simulations and measurements. Properties of dedicated tissue layers and geometrical body variations are investigated, and different electrodes are compared. The new intra-body communication technology has shown its feasibility in clinical trials. Excellent transmission was achieved between locations on the thorax with a typical signal-to-noise ratio (SNR) of 20 dB while the attenuation increased along the extremities.
Kinematic orbits and the structure of the internal space for systems of five or more bodies
Energy Technology Data Exchange (ETDEWEB)
Mitchell, Kevin A.; Littlejohn, Robert G.
1999-10-01
The internal space for a molecule, atom, or other n-body system can be conveniently parameterized by 3n - 9 kinematic angles and three hematic invariants. For a fixed set of kinematic invariants, the kinematic angles parameterize a subspace, called a kinematic orbit, of the n-body internal space. Building on an earlier analysis of the three- and four-body problems, we derive the form of these kinematic orbits (that is, their topology) for the general n-body problem. The case n = 5 is studied in detail, along with the previously studied cases n = 3,4.
The body force in a three-dimensional Lame' system: identification and regularization
Trong, Dang Duc; Thuc, Phung Trong
2011-01-01
Let a three-dimensional isotropic elastic body be described by the Lam\\'e system with the body force of the form $F(x,t)=\\phi(t)f(x)$, where $\\phi$ is known. We consider the problem of determining the unknown spatial term $f(x)$ of the body force where the surface stress history is given as the overdetermination. This inverse problem is ill-posed. Using the interpolation method and truncated Fourier series, we construct a regularized solution from approximate data and provide explicit error estimates. AMS 2010 Subject Classification: 35L20, 35R30. Keywords: Body force, elastic, ill$-$posed problem, interpolation, Fourier series.
Singularity free N-body simulations called 'Dynamic Universe Model' don't require dark matter
Naga Parameswara Gupta, Satyavarapu
For finding trajectories of Pioneer satellite (Anomaly), New Horizons satellite going to Pluto, the Calculations of Dynamic Universe model can be successfully applied. No dark matter is assumed within solar system radius. The effect on the masses around SUN shows as though there is extra gravitation pull toward SUN. It solves the Dynamics of Extra-solar planets like Planet X, satellite like Pioneer and NH for 3-Position, 3-velocity 3-accelaration for their masses, considering the complex situation of Multiple planets, Stars, Galaxy parts and Galaxy centre and other Galaxies Using simple Newtonian Physics. It already solved problems Missing mass in Galaxies observed by galaxy circular velocity curves successfully. Singularity free Newtonian N-body simulations Historically, King Oscar II of Sweden an-nounced a prize to a solution of N-body problem with advice given by Güsta Mittag-Leffler in 1887. He announced `Given a system of arbitrarily many mass points that attract each according to Newton's law, under the assumption that no two points ever collide, try to find a representation of the coordinates of each point as a series in a variable that is some known function of time and for all of whose values the series converges uniformly.'[This is taken from Wikipedia]. The announced dead line that time was1st June 1888. And after that dead line, on 21st January 1889, Great mathematician Poincaré claimed that prize. Later he himself sent a telegram to journal Acta Mathematica to stop printing the special issue after finding the error in his solution. Yet for such a man of science reputation is important than money. [ Ref Book `Celestial mechanics: the waltz of the planets' By Alessandra Celletti, Ettore Perozzi, page 27]. He realized that he has been wrong in his general stability result! But till now nobody could solve that problem or claimed that prize. Later all solutions resulted in singularities and collisions of masses, given by many people
Demerdash, Omar; Head-Gordon, Teresa
2016-08-09
We analyze convergence of energies and forces for the AMOEBA classical polarizable model when evaluated as a many-body expansion (MBE) against the corresponding N-body parent potential in the context of a condensed-phase water simulation. This is in contrast to most MBE formulations based on quantum mechanics, which focus only on convergence of energies for gas-phase clusters. Using a single water molecule as a definition of a body, we find that truncation of the MBE at third order, 3-AMOEBA, captures direct polarization exactly and yields apparent good convergence of the mutual polarization energy. However, it renders large errors in the magnitude of polarization forces and requires at least fourth-order terms in the MBE to converge toward the parent potential gradient values. We can improve the convergence of polarization forces for 3-AMOEBA by embedding the polarization response of dimers and trimers within a complete representation of the fixed electrostatics of the entire system. We show that the electrostatic embedding formalism helps identify the specific configurations involving linear hydrogen-bonding arrangements that are poorly convergent at the 3-body level. By extending the definition of a body to be a large water cluster, we can reduce errors in forces to yield an approximate polarization model that is up to 10 times faster than the parent potential. The 3-AMOEBA model offers new ways to investigate how the properties of bulk water depend on the degree of connectivity in the liquid.
Model Reduction of Hybrid Systems
DEFF Research Database (Denmark)
Shaker, Hamid Reza
High-Technological solutions of today are characterized by complex dynamical models. A lot of these models have inherent hybrid/switching structure. Hybrid/switched systems are powerful models for distributed embedded systems design where discrete controls are applied to continuous processes...... of hybrid systems, designing controllers and implementations is very high so that the use of these models is limited in applications where the size of the state space is large. To cope with complexity, model reduction is a powerful technique. This thesis presents methods for model reduction and stability....... Hybrid systems are also an important modeling class for nonlinear systems because a wide variety of nonlinearities are either piecewise-affine (e.g., a saturated linear actuator characteristic) or can be approximated as hybrid systems. The complexity of verifying and assessing general properties...
Modelling on fuzzy control systems
Institute of Scientific and Technical Information of China (English)
LI; Hongxing(李洪兴); WANG; Jiayin(王加银); MIAO; Zhihong(苗志宏)
2002-01-01
A kind of modelling method for fuzzy control systems is first proposed here, which is calledmodelling method based on fuzzy inference (MMFI). It should be regarded as the third modelling method thatis different from two well-known modelling methods, that is, the first modelling method, mechanism modellingmethod (MMM), and the second modelling method, system identification modelling method (SlMM). Thismethod can, based on the interpolation mechanism on fuzzy logic system, transfer a group of fuzzy inferencerules describing a practice system into a kind of nonlinear differential equation with variable coefficients, calledHX equations, so that the mathematical model of the system can be obtained. This means that we solve thedifficult problem of how to get a model represented as differential equations on a complicated or fuzzy controlsystem.
BOUSSINESQ MODELLING OF NEARSHORE WAVES UNDER BODY FITTED COORDINATE
Institute of Scientific and Technical Information of China (English)
FANG Ke-zhao; ZOU Zhi-li; LIU Zhong-bo; YIN Ji-wei
2012-01-01
A set of nonlinear Boussinesq equations with fully nonlinearity property is solved numerically in generalized coordinates,to develop a Boussinesq-type wave model in dealing with irregular computation boundaries in complex nearshore regions and to facilitate the grid refinements in simulations.The governing equations expressed in contravariant components of velocity vectors under curv ilinear coordinates are derived and a high order finite difference scheme on a staggered grid is employed for the numerical implementation.The developed model is used to simulate nearshore wave propagations under curvilinear coordinates,the numerical results are compared against analytical or experimental data with a good agreement.
Partial Dynamical Symmetry in a Fermionic Many-Body System
Escher, J
2000-01-01
The concept of partial symmetry is introduced for an interacting fermion system. The associated Hamiltonians are shown to be closely related to a realistic nuclear quadrupole-quadrupole interaction. An application to $^{12}$C is presented.
Energy System Modeling with REopt
Energy Technology Data Exchange (ETDEWEB)
Simpkins, Travis; Anderson, Kate; Cutler, Dylan; Olis, Dan; Elgqvist, Emma; DiOrio, Nick; Walker, Andy
2016-07-15
This poster details how REopt - NREL's software modeling platform for energy systems integration and optimization - can help to model energy systems. Some benefits of modeling with REopt include optimizing behind the meter storage for cost and resiliency, optimizing lab testing, optimizing dispatch of utility scale storage, and quantifying renewable energy impact on outage survivability.
Energy Technology Data Exchange (ETDEWEB)
Appel, H.
2007-05-15
In part I of this work we present a double-pole approximation (DPA) to the response equations of time-dependent density functional theory (TDDFT). The double-pole approximation provides an exact description of systems with two strongly coupled excitations which are isolated from the rest of the spectrum. In contrast to the traditional single-pole approximation of TDDFT the DPA also yields corrections to the Kohn-Sham oscillator strengths. We also demonstrate how to invert the double-pole solution which allows us to predict matrix elements of the exchange-correlation kernel f{sub xc} from experimental input. We attempt some first steps towards a time-dependent generalization of reduced density matrix functional theory (RDMFT). In part II we derive equations of motion for natural orbitals and occupation numbers. Using the equation of motion for the occupation numbers we show that an adiabatic extension of presently known ground-state functionals of static RDMFT always leads to occupation numbers which are constant in time. From the stationary conditions of the equations of motion for the N-body correlations (correlated parts of the N-body matrices) we derive a new class of ground-state functionals which can be used in static RDMFT. Applications are presented for a one-dimensional model system where the time-dependent many-body Schroedinger equation can be propagated numerically. We use optimal control theory to find optimized laser pulses for transitions in a model for atomic Helium. From the numerically exact correlated wavefunction we extract the exact time evolution of natural orbitals and occupation numbers for (i) laser-driven Helium and (ii) electron-ion scattering. Part III of this work considers time-dependent quantum transport within TDDFT. We present an algorithm for the calculation of extended eigenstates of single-particle Hamiltonians which is especially tailored to a finite-difference discretization of the Schroedinger equation. We consider the
Towards many-body based nuclear reaction modelling
Hilaire, Stéphane; Goriely, Stéphane
2016-06-01
The increasing need for cross sections far from the valley of stability poses a challenge for nuclear reaction models. So far, predictions of cross sections have relied on more or less phenomenological approaches, depending on parameters adjusted to available experimental data or deduced from systematic expressions. While such predictions are expected to be reliable for nuclei not too far from the experimentally known regions, it is clearly preferable to use more fundamental approaches, based on sound physical principles, when dealing with very exotic nuclei. Thanks to the high computer power available today, all the ingredients required to model a nuclear reaction can now be (and have been) microscopically (or semi-microscopically) determined starting from the information provided by a nucleon-nucleon effective interaction. This concerns nuclear masses, optical model potential, nuclear level densities, photon strength functions, as well as fission barriers. All these nuclear model ingredients, traditionally given by phenomenological expressions, now have a microscopic counterpart implemented in the TALYS nuclear reaction code. We are thus now able to perform fully microscopic cross section calculations. The quality of these ingredients and the impact of using them instead of the usually adopted phenomenological parameters will be discussed. Perspectives for the coming years will be drawn on the improvements one can expect.
Yukawa model on a lattice: two body states
De Soto, F; Roiesnel, C; Boucaud, P; Leroy, J P; Pène, O; Boucaud, Ph.
2007-01-01
We present first results of the solutions of the Yukawa model as a Quantum Field Theory (QFT) solved non perturbatively with the help of lattice calculations. In particular we will focus on the possibility of binding two nucleons in the QFT, compared to the non relativistic result.
Body cooling, modelling & risk assessment - Immersion Hypothermia Chapter
Tikuisis, P; Daanen, H.A.M.
2014-01-01
This chapter describes a model that can be used to predict hypothermia during cold water immersion. Drowning in cold water might precede the onset of hypothermia due to cold shock, injury or incapacitation. As pointed out in Chap. 129, there are three phases of increasing incapacitation leading to l
Stooke Small Body Shape Models V2.0
Stooke, P.
2016-10-01
This data set contains Philip Stooke shape models for 243 Ida, 253 Mathilde, 951 Gaspra, comet Halley, J5 Amalthea, J14 Thebe, N7 Larissa, N8 Proteus, S10 Janus, S11 Epimetheus, S16 Prometheus, and S17 Pandora, based on optical data from the NEAR, Galileo, Giotto, Vega 1, Vega 2, and Voyager missions.
Spectral element modelling of floating bodies in a Boussinesq framework
DEFF Research Database (Denmark)
Engsig-Karup, Allan Peter; Eskilsson, Claes; Ricchiuto, Mario
The wave energy sector relies heavily on the use of linear hydrodynamic models for the assessment of motions, loads and power production. The linear codes are computationally efficient and produce good results if applied within their application window. However, recent studies using two-phase VOF...
A mathematical human body model for frontal and rearward seated automotive impact loading
Happee, R.; Hoofman, R.; Kroonenberg, A.J. van den; Morsink, P.L.J.; Wismans, J.S.H.M.
1998-01-01
Mathematical modelling is widely used for crash-safety research and design. However, most occupant models used in crash simulations are based on crash dummies and thereby inherit their apparent limitations. Several models simulating parts of the real human body have been published, but only few desc
Comparison of estimates of body fat content in childhood-onset systemic lupus erythematosus.
Sinicato, N A; Peres, F A; de Oliveira Peliçari, K; de Oliveira Santos, A; Ramos, C D; Marini, R; Appenzeller, S
2017-04-01
Objective We aimed to compare estimates of body fat content with respect to their ability to predict the percentage of body fat, confirmed by dual-energy X-ray absorptiometry scans in childhood-onset systemic lupus erythematosus. Methods We included 64 consecutive childhood-onset systemic lupus erythematosus patients and 64 healthy age and sex-matched controls in a cross-sectional study. Anthropometric data, body mass index and body adiposity index were calculated for all subjects. Childhood-onset systemic lupus erythematosus patients were further assessed for clinical and laboratory childhood-onset systemic lupus erythematosus manifestations and fat mass, lean mass and percentage of body fat evaluated by dual-energy X-ray absorptiometry. Results Elevated waist/hip ratio was observed in childhood-onset systemic lupus erythematosus patients when compared to controls ( p systemic lupus erythematosus patients and controls. Using dual-energy X-ray absorptiometry as gold standard we observed that all indirect estimates of body fat were correlated with whole body fat mass. We observed a correlation between height and cumulative corticosteroid dose adjusted by weight ( r = 0.429, p = 0.005) in childhood-onset systemic lupus erythematosus. On whole body analysis we observed a correlation between lean mass and ACR Damage Index scores ( r = -0.395; p = 0.019); percentage of body fat and adjusted Systemic Lupus Erythematosus Disease Activity Index ( r = 0.402; p = 0.008), disease duration ( r = -0.370; p = 0.012). On trunk analysis we observed a correlation between lean mass and ACR Damage Index ( r = -0.319; p = 0.042); percentage of body fat with adjusted Systemic Lupus Erythematosus Disease Activity Index ( r = 0.402; p = 0.005), disease duration ( r = -0.408; p = 0.005). Conclusions This is the first study analyzing body adiposity index in childhood-onset systemic lupus erythematosus patients. We observed that all
Stochastic many-body problems in ecology, evolution, neuroscience, and systems biology
Butler, Thomas C.
Using the tools of many-body theory, I analyze problems in four different areas of biology dominated by strong fluctuations: The evolutionary history of the genetic code, spatiotemporal pattern formation in ecology, spatiotemporal pattern formation in neuroscience and the robustness of a model circadian rhythm circuit in systems biology. In the first two research chapters, I demonstrate that the genetic code is extremely optimal (in the sense that it manages the effects of point mutations or mistranslations efficiently), more than an order of magnitude beyond what was previously thought. I further show that the structure of the genetic code implies that early proteins were probably only loosely defined. Both the nature of early proteins and the extreme optimality of the genetic code are interpreted in light of recent theory [1] as evidence that the evolution of the genetic code was driven by evolutionary dynamics that were dominated by horizontal gene transfer. I then explore the optimality of a proposed precursor to the genetic code. The results show that the precursor code has only limited optimality, which is interpreted as evidence that the precursor emerged prior to translation, or else never existed. In the next part of the dissertation, I introduce a many-body formalism for reaction-diffusion systems described at the mesoscopic scale with master equations. I first apply this formalism to spatially-extended predator-prey ecosystems, resulting in the prediction that many-body correlations and fluctuations drive population cycles in time, called quasicycles. Most of these results were previously known, but were derived using the system size expansion [2, 3]. I next apply the analytical techniques developed in the study of quasi-cycles to a simple model of Turing patterns in a predator-prey ecosystem. This analysis shows that fluctuations drive the formation of a new kind of spatiotemporal pattern formation that I name "quasi-patterns." These quasi
Rheumatoid Arthritis When Your Immune System Attacks Your Body | NIH MedlinePlus the Magazine
... page please turn JavaScript on. Feature: Understanding Rheumatoid Arthritis (RA) Rheumatoid Arthritis When Your Immune System Attacks Your Body Past ... are prone to fracture). Source: NIAMS Who Gets Rheumatoid Arthritis? The disease occurs in all racial and ethnic ...
Augmented Eigenvector and Its Orthogonality of Linear Multi-rigid-flexibel-body System
Institute of Scientific and Technical Information of China (English)
RUI Xiao-ting; YUN Lai-feng; WANG Guo-ping; LU Yu-qi
2008-01-01
The orthogonality of eigenvector is a precondition to compute the dynamic responses of linear multi-rigid-flexible-body system using the classical modal analysis method. For a linear multi-rigid-flexible-body system, the eigenfunction does not satisfy the orthogonality under ordinary meaning. A new concept--augmented eigenvector is introduced, which is used to overcome the orthogonality problem of eigenvectors of linear multi-rigid-flexible-body system. The constitution method and the orthogonality of augmented eigenvector are expatiated. After the orthogonality of augmented eigenvector is acquired, the coupling of coordinates in dynamics equations can be released, which makes it possible to analyze exactly the dynamic responses of linear multi-rigid-flexible-body system using the classical modal analysis method.
Spacecraft/Rover Hybrids for the Exploration of Small Solar System Bodies Project
National Aeronautics and Space Administration — The objective of this effort is to develop a mission architecture that allows the systematic and affordable in situ exploration of small Solar System bodies (such...
Bound Motion of Bodies and Paticles in the Rotating Systems
Pardy, Miroslav
2007-04-01
The Lagrange theory of particle motion in the noninertial systems is applied to the Foucault pendulum, isosceles triangle pendulum and the general triangle pendulum swinging on the rotating Earth. As an analogue, planet orbiting in the rotating galaxy is considered as the giant galactic gyroscope. The Lorentz equation and the Bargmann-Michel-Telegdi equations are generalized for the rotation system. The knowledge of these equations is inevitable for the construction of LHC where each orbital proton “feels” the Coriolis force caused by the rotation of the Earth.
Anisotropic static solutions in modelling highly compact bodies
Indian Academy of Sciences (India)
M Chaisi; S D Maharaj
2006-03-01
Einstein field equations for static anisotropic spheres are solved and exact interior solutions obtained. This paper extends earlier treatments to include anisotropic models which accommodate a wider variety of physically viable energy densities. Two classes of solutions are possible. The first class contains the limiting case ∝ -2 for the energy density which arises in many astrophysical applications. In the second class the singularity at the centre of the star is not present in the energy density
Three-body recombination at finite energy within an optical model
Sørensen, P. K.; Fedorov, D. V.; Jensen, A. S.; Zinner, N. T.
2013-10-01
We investigate three-boson recombination of equal mass systems as function of (negative) scattering length, mass, finite energy, and finite temperature. An optical model with an imaginary potential at short distance reproduces experimental recombination data and allows us to provide a simple parametrization of the recombination rate as function of scattering length and energy. Using the two-body van der Waals length as unit we find that the imaginary potential range and also the potential depth agree to within 30% for lithium and cesium atoms. As opposed to recent studies suggesting universality of the threshold for bound-state formation, our results suggest that the recombination process itself could have universal features.
3D and 4D atlas system of living human body structure.
Suzuki, N; Takatsu, A; Hattori, A; Ezumi, T; Oda, S; Yanai, T; Tominaga, H
1998-01-01
A reference system for accessing anatomical information from a complete 3D structure of the whole body "living human", including 4D cardiac dynamics, was reconstructed with 3D and 4D data sets obtained from normal volunteers. With this system, we were able to produce a human atlas in which sectional images can be accessed from any part of the human body interactively by real-time image generation.
Formation of three-body entanglement via a vacuum optical cavity induction in Tavis-Cummings model
Institute of Scientific and Technical Information of China (English)
Li Yu-Liang; Li Xue-Mei
2008-01-01
After briefly introducing Akhtarshenas, concurrence vector and subvector for describing many-body entanglement,we investigate the entanglement formation for a system which contains three bodies, i.e. two identical atoms and a single model cavity field, in the Tavis-Cummings model by calculating the concurrences. The results show that the coupling strength between two atoms, the decay cavity and the atomic spontaneous emission can change the entanglement of formation according to different modes: these factors destroy periodicity and symmetry of all concurrences, and that the coupling strength of two atoms does not change the peak value of concurrence (C), but the strength of decay cavity and the atomic spontaneous emission decline in the peak value of concurrence (C) and the latter is more serious than the former under the same strengths. The concurrence vector and subvector are a useful measure of entanglement for a pure state of the many-body system, in that it can give novel pictures about the entanglements for the entire system and between its inner bodies.
Long-distance entanglement in many-body atomic and optical systems
Giampaolo, Salvatore M
2009-01-01
We discuss the phenomenon of long-distance entanglement in the ground state of quantum spin models, its use in high-fidelity and robust quantum communication, and its realization in many-body systems of ultracold atoms in optical lattices and in arrays of coupled optical cavities. We investigate different patterns of site-dependent interaction couplings, singling out two general settings: Patterns that allow for perfect long-distance entanglement (LDE) in the ground state of the system, namely such that the end-to-end entanglement remains finite in the thermodynamic limit, and patterns of quasi long-distance entanglement (QLDE) in the ground state of the system, namely, such such that the end-to-end entanglement vanishes with a very slow power-law decay as the length of the spin chain is increased. We discuss physical realizations of these models in ensembles of ultracold bosonic atoms loaded in optical lattices. We show how, using either suitably engineered super-lattice structures or exploiting the presence...
Determining properties of the Antennae system - Merging ability for restricted N-body
Petsch, H. P.; Theis, C.
2011-01-01
Motivated by the closest major merger, the Antennae Galaxies (NGC4038/4039), we want to improve our genetic algorithm based modeling code Minga (Theis 1999). The aim is to reveal the major interaction and galaxy parameters, e.g. orbital information and halo properties of such an equal mass merger system. Together with the sophisticated search strategy of Minga, one needs fast and reliable models in order to investigate the high dimensional parameter space of this problem. Therefore we use a restricted N-body code which is based on the approach by Toomre & Toomre (1972), however with some refinements like consistent orbits of extended dark matter halos. Recently also dynamical friction was included to this code (Petsch 2007). While a good description for dynamical friction was found for mass ratios up to q = 1/3 (Petsch & Theis 2008), major merger systems were only imperfectly remodeled. Here we show recent improvements for a major merger system by including mass-loss and using NFW halos.
Determining properties of the Antennae system - Merging ability for restricted N-body
Petsch, Hanns P
2008-01-01
Motivated by the closest major merger, the Antennae Galaxies (NGC4038/4039), we want to improve our genetic algorithm based modeling code Minga (Theis 1999). The aim is to reveal the major interaction and galaxy parameters, e.g. orbital information and halo properties of such an equal mass merger system. Together with the sophisticated search strategy of Minga, one needs fast and reliable models in order to investigate the high dimensional parameter space of this problem. Therefore we use a restricted N-body code which is based on the approach by Toomre & Toomre (1972), however with some refinements like consistent orbits of extended dark matter halos. Recently also dynamical friction was included to this code (Petsch 2007). While a good description for dynamical friction was found for mass ratios up to q = 1/3 (Petsch & Theis 2008), major merger systems were only imperfectly remodeled. Here we show recent improvements for a major merger system by including mass-loss and using NFW halos.
Incorporation of Active Elements into the Articulated Total Body Model.
1985-06-30
one muscle/harness system representing the biceps brachii and the brachialis. The results indicated that the force velocity effects produced the...Production by the Biceps during Eccentric Motion ... .... .53 vii LIST OF TABLES Table Page - 1 Specifications on Elbow Musculature...z disks does not allow appreciable movement. The tendinous parts of the muscle fiber are located near the origin and insertion of the fiber and thus
Matrix Pseudospectral Method for (Visco)Elastic Tides Modeling of Planetary Bodies
Zabranova, Eliska; Hanyk, Ladidslav; Matyska, Ctirad
2010-05-01
We deal with the equations and boundary conditions describing deformation and gravitational potential of prestressed spherically symmetric elastic bodies by decomposing governing equations into a series of boundary value problems (BVP) for ordinary differential equations (ODE) of the second order. In contrast to traditional Runge-Kutta integration techniques, highly accurate pseudospectral schemes are employed to directly discretize the BVP on Chebyshev grids and a set of linear algebraic equations with an almost block diagonal matrix is derived. As a consequence of keeping the governing ODEs of the second order instead of the usual first-order equations, the resulting algebraic system is half-sized but derivatives of the model parameters are required. Moreover, they can be easily evaluated for models, where structural parametres are piecewise polynomially dependent. Both accuracy and efficiency of the method are tested by evaluating the tidal Love numbers for the Earth's model PREM. Finally, we also derive complex Love numbers for models with the Maxwell viscoelastic rheology, where viscosity is a depth-dependent function. The method is applied to evaluation of the tidal Love numbers for models of Mars and Venus. The Love numbers of the two Martian models - the former optimized to cosmochemical data and the latter to the moment of inertia (Sohl and Spohn, 1997) - are h2=0.172 (0.212) and k2=0.093 (0.113). For Venus, the value of k2=0.295 (Konopliv and Yoder, 1996), obtained from the gravity-field analysis, is consistent with the results for our model with the liquid-core radius of 3110 km (Zábranová et al., 2009). Together with rapid evaluation of free oscillation periods by an analogous method, this combined matrix approach could by employed as an efficient numerical tool in structural studies of planetary bodies. REFERENCES Konopliv, A. S. and Yoder, C. F., 1996. Venusian k2 tidal Love number from Magellan and PVO tracking data, Geophys. Res. Lett., 23, 1857
Quantum optical feedback control for creating strong correlations in many-body systems
Mazzucchi, Gabriel; Ivanov, Denis A; Mekhov, Igor B
2016-01-01
Light enables manipulating many-body states of matter, and atoms trapped in optical lattices is a prominent example. However, quantum properties of light are completely neglected in all quantum gas experiments. Extending methods of quantum optics to many-body physics will enable phenomena unobtainable in classical optical setups. We show how using the quantum optical feedback creates strong correlations in bosonic and fermionic systems. It balances two competing processes, originating from different fields: quantum backaction of weak optical measurement and many-body dynamics, resulting in stabilized density waves, antiferromagnetic and NOON states. Our approach is extendable to other systems promising for quantum technologies.
The Solar Poynting-Robertson Effect On Particles Orbiting Solar System Bodies: Circular Orbits
Rubincam, David P.
2013-01-01
The Poynting-Robertson effect from sunlight impinging directly on a particle which orbits a Solar System body (planet, asteroid, comet) is considered from the Sun's rest frame. There appear to be no significant first-order terms in V(sub b)/c for circular orbits, where V(sub b) is the body's speed in its orbit about the Sun and c is the speed of light, when the particle's orbital semimajor axis is much smaller than the body's orbital semimajor axis about the Sun as is mainly the case in the Solar System.
Polarimetric Exploration of Solar System Small Bodies: Search for Habitability
Yanamandra-Fisher, Padma A.
2015-08-01
The overarching goals for the remote sensing and robotic exploration of our solar system and exoplanetary systems are: (1) understanding the formation of planetary systems and their diversity; and (2) search for habitability. These goals can be realized with the inclusion of spectrophotopolarimetry as a complementary approach to standard techniques of imaging and spectroscopy. Since all objects have unique polarimetric signatures, like fingerprints, much can be learned about the scattering object. Although polarization, in general, is elliptical by nature, special cases such as linear and circular polarimetric signatures provide insight into the various types of scattering media and are valuable tools to be developed. Additionally, spectral dependence of polarization is important to separate the macroscopic (bulk) properties of the scattering medium from the microscopic (particulate) properties of the scattering medium. The search for habitability can benefit from spectrophotopolarimetry. While linear polarization of reflected light by solar system objects (planetary atmospheres, satellites, rings systems, comets, asteroids, dust, etc.) provides insight into the scattering characteristics of aerosols and hazes in atmospheres and surficial properties of atmosphereless objects, circular polarization and related chirality) or handedness, a property of molecules that exhibit mirror-image symmetry, similar to right and left hands) can serve as diagnostic of biological activity. All known life forms on earth are chiral and pre-dominantly left-handed. However, many of these applications suffer from lack of detailed observations, instrumentation, dedicated missions and numerical/retrieval methods. I will present a review of the field, with advances made in instrumentation, measurements and applications to prospective missions.
Validation of systems biology models
Hasdemir, D.
2015-01-01
The paradigm shift from qualitative to quantitative analysis of biological systems brought a substantial number of modeling approaches to the stage of molecular biology research. These include but certainly are not limited to nonlinear kinetic models, static network models and models obtained by the
Patient-specific biomechanical model as whole-body CT image registration tool.
Li, Mao; Miller, Karol; Joldes, Grand Roman; Doyle, Barry; Garlapati, Revanth Reddy; Kikinis, Ron; Wittek, Adam
2015-05-01
Whole-body computed tomography (CT) image registration is important for cancer diagnosis, therapy planning and treatment. Such registration requires accounting for large differences between source and target images caused by deformations of soft organs/tissues and articulated motion of skeletal structures. The registration algorithms relying solely on image processing methods exhibit deficiencies in accounting for such deformations and motion. We propose to predict the deformations and movements of body organs/tissues and skeletal structures for whole-body CT image registration using patient-specific non-linear biomechanical modelling. Unlike the conventional biomechanical modelling, our approach for building the biomechanical models does not require time-consuming segmentation of CT scans to divide the whole body into non-overlapping constituents with different material properties. Instead, a Fuzzy C-Means (FCM) algorithm is used for tissue classification to assign the constitutive properties automatically at integration points of the computation grid. We use only very simple segmentation of the spine when determining vertebrae displacements to define loading for biomechanical models. We demonstrate the feasibility and accuracy of our approach on CT images of seven patients suffering from cancer and aortic disease. The results confirm that accurate whole-body CT image registration can be achieved using a patient-specific non-linear biomechanical model constructed without time-consuming segmentation of the whole-body images.
Efimov States in Three-body Systems%三体系统中的Efimov态
Institute of Scientific and Technical Information of China (English)
陈双; 任中洲; 许昌
2009-01-01
We studied the Efimov effect in a three-body system by solving the Faddeev equations.Different models and interactions were considered. The occurrence of Efimov states was discussed.The possible Efimov state was clearly presented and its properties were investigated.%通过求解Faddeev方程,研究了量子三体系统中的Efimov效应.改进了变分方法对于求解激发态的不足.在不同的两体作用下得到了三体系统中的Efimov态.讨论了在不同质量比的三体系统中出现Efimov态的条件.并由三体计算的结果分析了具有两个价中子的核系统在两体存在束缚态时可能存在的Efimov效应.
Energy Technology Data Exchange (ETDEWEB)
Litvak, M.L., E-mail: litvak@mx.iki.rssi.ru [Space Research Institute, RAS, Moscow 117997 (Russian Federation); Golovin, D.V. [Space Research Institute, RAS, Moscow 117997 (Russian Federation); Jun, I. [Jet Propulsion Laboratory, Pasadena, CA (United States); Kozyrev, A.S.; Mitrofanov, I.G.; Sanin, A.B. [Space Research Institute, RAS, Moscow 117997 (Russian Federation); Shvetsov, V.N.; Timoshenko, G.N.; Zontikov, A. [Joint Institute for Nuclear Research, Dubna (Russian Federation)
2016-06-21
In this paper we present the results of ground tests performed with a flight model and with industry prototypes of passive and active gamma ray spectrometers with the objective of understanding their capability to distinguish the elemental composition of planetary bodies in the solar system. The gamma instrumentation, which was developed for future space missions was used in the measurements at a special ground test facility where a simulant of planetary material was fabricated with a martian-like composition. In this study, a special attention was paid to the gamma lines from activation reaction products generated by a pulsed neutron generator. The instrumentation was able to detect and identify gamma lines attributed to O, Na, Mg, Al, Si, K, Ca and Fe.
Evolution of pairwise entanglement in a coupled n -body system
Pineda, Carlos; Seligman, Thomas H.
2006-01-01
We study the exact evolution of two noninteracting qubits, initially in a Bell state, in the presence of an environment, modeled by a kicked Ising spin chain. Dynamics of this model range from integrable to chaotic and we can handle numerics for a large number of qubits. We find that the entanglement (as measured by concurrence) of the two qubits has a close relation to the purity of the pair, and closely follows an analytic relation derived for Werner states. As a collateral result we find that an integrable environment causes quadratic decay of concurrence as well as of purity, while a chaotic environment causes linear decay. Both quantities display recurrences in an integrable environment.
From Numeric Models to Granular System Modeling
Directory of Open Access Journals (Sweden)
Witold Pedrycz
2015-03-01
To make this study self-contained, we briefly recall the key concepts of granular computing and demonstrate how this conceptual framework and its algorithmic fundamentals give rise to granular models. We discuss several representative formal setups used in describing and processing information granules including fuzzy sets, rough sets, and interval calculus. Key architectures of models dwell upon relationships among information granules. We demonstrate how information granularity and its optimization can be regarded as an important design asset to be exploited in system modeling and giving rise to granular models. With this regard, an important category of rule-based models along with their granular enrichments is studied in detail.
Efficient Cartesian-grid-based modeling of rotationally symmetric bodies
DEFF Research Database (Denmark)
Shyroki, Dzmitry
2007-01-01
Axially symmetric waveguides, resonators, and scatterers of arbitrary cross section and anisotropy in the cross section can be modeled rigorously with use of 2-D Cartesian-grid based codes by means of mere redefinition of material permittivity and permeability profiles. The method is illustrated...... by the frequencydomain simulations of resonant modes in a circular-cylinder cavity with perfectly conducting walls, a shielded uniaxial anisotropic dielectric cylinder, and an open dielectric sphere for which, after proper implementation of the perfectly matched layer boundary conditions, the radiation quality factor...
Body-weight distribution on forelimbs in rat tail-suspension model.
Sun, Lian-Wen; Wang, Chao; Xie, Tian; Pu, Fang; Sun, Yao; Fan, Yu-Bo
2010-01-01
To understand the tail-suspension model to simulate weightlessness better, this study was to investigate the relationship of the amount of body weight supported by forelimbs between the tilt angles of rat in the model. Normal rat had at least two basic postures. One was standing or walking, in which the forelimbs bear 44.6% of the body weight; the other one was resting, in which 23.9% of body weight was placed on the forelimbs. As for tail-suspended rat, body-weight distribution on forelimbs was linearly related to tilt angle. The linear relationship was y = -0.7423x + 70.849, R2 = 0.9269. The tilt angle should be approximately 35 degrees if normal standing load of 44.6% body weight was placed on the forelimbs. On the other hand, it should be approximately 63 degrees if normal resting load of 23.9% of body weight was placed on forelimbs. Furthermore, the body load on forelimbs in tail-suspension model became much larger if the period of different postures was considered. Therefore, it should be careful if forelimbs are used to be as convenient internal control in tail-suspended rats.
Modeling of deterministic chaotic systems
Energy Technology Data Exchange (ETDEWEB)
Lai, Y. [Department of Physics and Astronomy and Department of Mathematics, The University of Kansas, Lawrence, Kansas 66045 (United States); Grebogi, C. [Institute for Plasma Research, University of Maryland, College Park, Maryland 20742 (United States); Grebogi, C.; Kurths, J. [Department of Physics and Astrophysics, Universitaet Potsdam, Postfach 601553, D-14415 Potsdam (Germany)
1999-03-01
The success of deterministic modeling of a physical system relies on whether the solution of the model would approximate the dynamics of the actual system. When the system is chaotic, situations can arise where periodic orbits embedded in the chaotic set have distinct number of unstable directions and, as a consequence, no model of the system produces reasonably long trajectories that are realized by nature. We argue and present physical examples indicating that, in such a case, though the model is deterministic and low dimensional, statistical quantities can still be reliably computed. {copyright} {ital 1999} {ital The American Physical Society}
Calculation of local pressure tensors in systems with many-body interactions.
Heinz, Hendrik; Paul, Wolfgang; Binder, Kurt
2005-12-01
Local pressures are important in the calculation of interface tensions and in analyzing micromechanical behavior. The calculation of local pressures in computer simulations has been limited to systems with pairwise interactions between the particles, which is not sufficient for chemically detailed systems with many-body potentials such as angles and torsions. We introduce a method to calculate local pressures in systems with n-body interactions (n=2,3,4,) based on a micromechanical definition of the pressure tensor. The local pressure consists of a kinetic contribution from the linear momentum of the particles and an internal contribution from dissected many-body interactions by infinitesimal areas. To define dissection by a small area, respective n-body interactions are divided into two geometric centers, effectively reducing them to two-body interactions. Consistency with hydrodynamics-derived formulas for systems with two-body interactions [J. H. Irving and J. G. Kirkwood, J. Chem. Phys. 18, 817 (1950)], for average cross-sectional pressures [B. D. Todd, D. J. Evans, and P. J. Daivis, Phys. Rev. E 52, 1627 (1995)], and for volume averaged pressures (virial formula) is shown. As a simple numerical example, we discuss liquid propane in a cubic box. Local, cross-sectional, and volume-averaged pressures as well as relative contributions from two-body and three-body forces are analyzed with the proposed method, showing full numerical equivalence with the existing approaches. The method allows computing local pressures in the presence of many-body interactions in atomistic simulations of complex materials and biological systems.
Partial dynamical symmetries in quantal many-body systems
Energy Technology Data Exchange (ETDEWEB)
Van Isacker, P
2001-07-01
Partial dynamical symmetries are associated with Hamiltonians that are partially solvable. The determination of the properties of a quantal system of N interacting particles moving in an external potential requires the solution of the eigenvalue equation associated with a second-quantised Hamiltonian. In many situations of interest the Hamiltonian commutes with transformations that constitute a symmetry algebra G{sub sym}. This characteristic opens a way to find all analytically solvable Hamiltonians. The author gives a brief review of some recent developments.
Sadler, Katelyn E; Stratton, Jarred M; DeBerry, Jennifer J; Kolber, Benedict J
2013-01-01
Interstitial cystitis/bladder pain syndrome (IC/BPS) is a debilitating urological condition that is resistant to treatment and poorly understood. To determine novel molecular treatment targets and to elucidate the contribution of the nervous system to IC/BPS, many rodent bladder pain models have been developed. In this study we evaluated the effects of anesthesia induction and temperature variation in a mouse model of bladder pain known as urinary bladder distension (UBD). In this model compressed air is used to distend the bladder to distinct pressures while electrodes record the reflexive visceromotor response (VMR) from the overlying abdominal muscle. Two isoflurane induction models are commonly used before UBD: a short method lasting approximately 30 minutes and a long method lasting approximately 90 minutes. Animals were anesthetized with one of the methods then put through three sets of graded bladder distensions. Distensions performed following the short anesthesia protocol were significantly different from one another despite identical testing parameters; this same effect was not observed when the long anesthesia protocol was used. In order to determine the effect of temperature on VMRs, animals were put through three graded distension sets at 37.5 (normal mouse body temperature), 35.5, and 33.5°C. Distensions performed at 33.5 and 35.5°C were significantly lower than those performed at 37.5°C. Additionally, Western blot analysis revealed significantly smaller increases in spinal levels of phosphorylated extracellular-signal regulated kinase 2 (pERK2) following bladder distension in animals whose body temperature was maintained at 33.5°C as opposed to 37.5°C. These results highlight the significance of the dynamic effects of anesthesia on pain-like changes and the importance of close monitoring of temperature while performing UBD. For successful interpretation of VMRs and translation to human disease, body temperature should be maintained at 37.5