Transverse Motion Research Articles

Gravity Field (Low Frequency) of Planet Earth Described by Theory of New Axioms and Laws

The theory of new axioms and laws is published by the same author. It describes nonparametric and nonlinear processes and contains 2 new axioms and 8 new laws. Unlike Classical field theory, it describes longitudinal or transverse non-uniform motions which are accelerating or decelerating. According to the Axiom 1 every unevenly rotation of one vector forms open vortex which can be transverse or longitudinal and accelerating or decelerating. From the planetary model of Rutherford it is known that there is analogy between the electrons and an planets including the planet Earth. By analogy - the electrons and the internal planets are similar Gravitational bodies. According the Law 1 the model of the electron or the Earth represents a decelerating transverse vortex rolled into a plane (2D) and generating in its center accelerating longitudinal Gravity Funnel in (3D), perpendicular to the same plane. Inside- the primary accelerating longitudinal Gravity vectors are with decreasing dimensions and forms the decelerating Magnetic Field as a Back wave passing through the center of Earth. Outside- because of resistance of environment in periphery, is formed Back wave or decelerating Gravity vortex that passes outside the body of Earth. According Axiom 2 the reason for the creation of the electron is the generation by the corresponding proton. By analogythe reason for the creation of internal planets, including the planet Earth is in the generation of a specific vortex inside the corresponding for Earth resonator in the volume of the Sun. It is Low Frequency vortex which is formed in the third cylindrical resonator that corresponds to Earth. According Law 2 the proton or the resonator inside Sun is generated by a decelerating longitudinal vortex with direction from outside to inside which creates an accelerating transverse vortex from inside to outside in the perpendicular plane. As it is strongly accelerated this vortex from inside to outside it shoots itself into space in direction to the Earth. Due to the friction it decelerates and according to the previous Law 1 it winds into as a decelerating transverse vortex generating the body of Earth. According Law 5 decelerating vortex emits decelerating cross vortices from itself to outside. This decelerating vortices in periphery of the Earth emit energy and warm the center of the Earth. That is why the periphery of Earth is cool ,but the center of Earth is hot . According Law 6 the accelerating cross vortex sucks accelerating cross vortices to itself . This accelerating cross vortex at center of the Sun sucks energy and warm from center and emits them to periphery of Sun. That is why the center of Sun is cool but the periphery is extremely accelerated and hot. The described generating mechanism only applies to the inner planets. For the outer planets, the generation algorithm is orthogonal and will be described further.

Detection and manipulation of the transverse motion of neutral molecules in a Stark decelerator

By enabling precise control over longitudinal velocity of neutral molecules, Stark deceleration has become an important tool for studying cold molecular collisions. However, the information about transverse motion is often hard to extract and to some extent beyond control. Here we demonstrate a new experimental approach that allows us to observe the transverse phase-space distribution of molecules within a Stark decelerator. The transverse dynamics can be tracked along the decelerator, which can be used to measure the initial transverse phase-space distribution of the molecules. The observed frequency of the transverse oscillations agrees well with the one determined from electric field distribution. Thermalization of the molecules at the decelerator entrance must be accounted for in our Monte Carlo simulations of the molecules dynamics to reach agreement with experimental data. We introduce two approaches of manipulating transverse modes. In the first method, a free-flight pulse is introduced to achieve a short phase-space stretching, an equivalent technique to delta kick cooling [Phys. Rev. Lett. 78, 2088 (1997)]. In the second mode we enforce phase-space rotation by varying the applied voltage. Both modes allow us to manipulate the transverse phase-space distribution and, in particular, allow us to tune (in a well-controlled way) the anisotropy of the phase-space distribution.

Scraping hide in the early Upper Paleolithic: Insights into the life and function of the Protoaurignacian endscrapers at Fumane Cave

Endscrapers are specialized tools that are usually recovered in great quantities in every Upper Paleolithic site in Europe. Although they make their first ephemeral appearance in the Middle–late Middle Paleolithic transitional technocomplexes, endscrapers commonly appear in toolkits from initial and early Upper Paleolithic traditions onwards. Nevertheless, endscrapers and, in general, domestic tools have attracted relatively little attention in debates revolving around the significance of technological change, tool function, and tool specialization after the end of the Middle Paleolithic. With the aim to overcome this paucity of information, here, we present the results of a techno-functional study performed on the large endscraper assemblage recovered from the early and late Protoaurignacian layers at Fumane Cave in northeastern Italy. We analyzed these artifacts using technological, morpho-metrical, typological, and functional approaches. Despite the large morphological variability, use-wear traces reveal functional consistency and high levels of specialization for these tools. Almost all the use-wear traces we recorded developed from hide working with transverse motion. Moreover, we find no evidence that endscrapers were involved in the production of bone and antler tools during the late Protoaurignacian. Macroscopic and microscopic wear on the lateral edges of tools point to a considerable number of hafted endscrapers, which implies systematic time investment and planning depth. Comparison with the few endscrapers from transitional industries that have been analyzed highlights marked differences in the production, morphology, and use of these tools and reinforces our view of the Aurignacian as a complex not directly related with preceding European traditions.

Energy harvesting from longitudinal and transverse motions of sea waves particles using a new waterproof piezoelectric waves energy harvester

This paper experimentally studied the energy harvesting from the longitudinal and transverse motions of sea waves using a waterproof piezoelectric wave energy harvester (WPWEH). Because of sealing and specific design type of the WPWEH, the piezoelectric cantilever beam was entirely placed inside the water to increase the harvested electrical power. Three orientations of O1,O2 and O3were considered for placing the piezoelectric cantilever beam inside the water channel. In O1orientation, the cantilever beam was vertical and perpendicular to the floor while in O2and O3orientations, it was horizontal and parallel with the floor. The cantilever beam was perpendicular to the flow in O1andO2 and vibrates due to the longitudinal motion of wave particles while it was parallel with the flow in O3 and vibrates due to the transverse motion of wave particles. The influence of orientation, wave rate, and resonant frequency of the cantilever beam on the root mean square of the voltage and harvested electrical power was studied. The O1 orientation was selected as the optimum orientation for energy harvesting, because of having harmonic oscillations with a maximum generated voltage. The optimum electrical load resistance was calculated for the maximum harvested power. The results showed that the maximum density of the harvested electrical power from the WPWEH was increased compared to the other similar works.

Fluid flow and interface motion in gels: A finite-strain theory and its application to a channel flow problem

We present a theory for coupled deformation and liquid permeation in polymer gels, allowing for large strains and rotations in conjunction with sharp interfaces separating regions of high and low polymer volume fraction. The theory is applied to pressure-driven liquid flow through a gel-filled rectangular channel, with the aim of investigating how the elastic and osmotic properties of the gel influence the resulting permeation process. Apart from streamwise flow in the direction of the applied pressure drop, the permeation process may involve transverse flow if the elastic response of the gel allows the normal stress acting on a plane parallel to the channel walls to be affected by the shear stress acting on the same plane. For certain elastic energy densities, including those of neo-Hookean and Mooney type, liquid permeation takes place exclusively in the direction of the applied pressure drop. Otherwise, spanwise permeation driven by the contribution to the normal stress distributed on planes parallel to the channel walls is also present. In contrast to the downstream flow, the transverse flow is transient and is accompanied by changes in composition leading to a nonuniform polymer distribution across the channel and thereby influencing the downstream flow profile. By analyzing the instantaneous response of the gel, we determine the driving force for the transverse flow and show that for strain-stiffening networks the transverse motion of the interstitial liquid is directed inward from the channel walls and that the polymer network motion spreads outward from the center of the channel toward the walls. The opposite occurs for strain-slackening networks. By analyzing the steady-state response, we demonstrate that the applied pressure gradient leads to nonuniform transverse distributions of polymer chains than can be continuous or discontinuous. Discontinuous distributions occur for an effective osmotic response involving attractive interactions and are accompanied by the formation of regions of high and low polymer volume fraction separated by sharp interfaces. Finally, we provide illustrative examples for a gel whose elastic and osmotic responses are modeled by the Gent elastic energy density and the Flory–Huggins mixing energy density, respectively.

Superlattice on the surface of a nanotube

The results of theoretical studies of the thermodynamic, kinetic, and high-frequency properties of the electron gas on the surface of a nanotube in a magnetic field in the presence of a longitudinal superlattice are presented. Nano-dimensions of the motion area lead to energy quantization. Its multiply connected structure in the presence of a magnetic field leads to effects that are derived from the Aharonov–Bohm effect. It is shown that the curvature of a nanotube, even in the absence of a magnetic field, causes new macroscopic oscillation effects such as de Haas–van Alphen oscillations, which are associated with the quantization of the transverse electron motion energy and with the root peculiarities of the density of electron states on the nanotube surface. Thermodynamic potentials and heat capacity of the electron gas on the tube are calculated in the gas approximation. The Kubo formula for the conductivity tensor of the electron gas on the nanotube surface is obtained. The Landau damping regions of electromagnetic waves on a tube are determined and the beats are theoretically predicted on the graph of the dependence of conductivity on tube parameters. In the hydrodynamic approximation, the plasma waves on the surface of a semiconductor nanotube with a superlattice are considered. It is shown that optical and acoustic plasmons can propagate along a tube with one kind of carrier. Electron spin waves on the surface of a semiconductor nanotube with a superlattice in a magnetic field are studied. The spectra and areas of collisionless damping of these waves are found. We have shown that the spin wave damping is absent in these areas if the tubes with a degenerate electron gas have small radius.

Refined Mass and Geometric Measurements of the High-mass PSR J0740+6620

Abstract We report results from continued timing observations of PSR J0740+6620, a high-mass, 2.8 ms radio pulsar in orbit with a likely ultracool white dwarf companion. Our data set consists of combined pulse arrival-time measurements made with the 100 m Green Bank Telescope and the Canadian Hydrogen Intensity Mapping Experiment telescope. We explore the significance of timing-based phenomena arising from general relativistic dynamics and variations in pulse dispersion. When using various statistical methods, we find that combining ∼1.5 yr of additional, high-cadence timing data with previous measurements confirms and improves on previous estimates of relativistic effects within the PSR J0740+6620 system, with the pulsar mass m p = 2.08 − 0.07 + 0.07 M ⊙ (68.3% credibility) determined by the relativistic Shapiro time delay. For the first time, we measure secular variation in the orbital period and argue that this effect arises from apparent acceleration due to significant transverse motion. After incorporating contributions from Galactic differential rotation and off-plane acceleration in the Galactic potential, we obtain a model-dependent distance of d = 1.14 − 0.15 + 0.17 kpc (68.3% credibility). This improved distance confirms the ultracool nature of the white dwarf companion determined from recent optical observations. We discuss the prospects for future observations with next-generation facilities, which will likely improve the precision on m p for J0740+6620 by an order of magnitude within the next few years.

Lubrication analysis of peristaltic motion in non-axisymmetric annular tubes

This paper addresses peristaltic flow induced in a non-axisymmetric annular tube by a periodic small-amplitude wave of arbitrary shape propagating axially along its inner surface, assumed to be a circular cylinder. The study is motivated by recent in vivo experimental observations pertaining to the flow of cerebrospinal fluid along the perivascular spaces of cerebral arteries. The analysis employs the lubrication approximation, describing low-Reynolds-number peristaltic flow in the long-wavelength approximation. Closed-form analytic expressions are derived for the average pumping rate in infinitely long tubes and also in tubes of finite length. Consideration is also given to the transverse motion arising in non-axisymmetric tubes. For small-amplitude waves, the solution is reduced to the integration of a parameter-free Stokes-flow problem, which is solved for relevant cross-sectional shapes, with closed-form analytical results derived for thin canals.

Statistical Properties of the Transverse-Motion Energy Levels for Channeling Electrons in a Silicon Crystal under Dynamical Chaos Conditions

The classical motion of particles in external fields is frequently chaotic although deterministic within the classical limit. Studying the quantum mechanical behavior of such systems amounts to the problematics of quantum chaos. Quantum chaos manifests itself primarily in the statistical properties of the energy-level arrays of such systems. However, the typical objects under consideration are systems of the type billiards with rigid walls. This paper studies the calculated energy levels of the transverse motion of relativistic electrons in the axial-channeling regime along the [100] direction of the silicon crystal which is described as motion in the smooth potential well. The nearest-level spacing distributions as well as the spectral rigidity are studied for the range of parameters where electron motion is chaotic within the classical limit. Both these characteristics demonstrate agreement with quantum-chaos-theory predictions.

Thermoelectric properties of the (an-)isotropic QGP in magnetic fields

The Seebeck effect and the Nernst effect, which reflect the appearance of electric fields along x-axis and along y-axis (E_{x} and E_{y}), respectively, induced by the thermal gradient along x-axis, are studied in the QGP at an external magnetic field along z-axis. We calculate the associated Seebeck coefficient (S_{xx}) and Nernst signal (N) using the relativistic Boltzmann equation under the relaxation time approximation. In an isotropic QGP, the influences of magnetic field (B) and quark chemical potential (mu _{q}) on these thermoelectric transport coefficients are investigated. In the presence (absence) of weak magnetic field, we find S_{xx} for a fixed mu _{q} is negative (positive) in sign, indicating that the dominant carriers for converting heat gradient to electric field are negatively (positively) charged quarks. The absolute value of S_{xx} decreases with increasing temperature. Unlike S_{xx}, the sign of N is independent of charge carrier type, and its thermal behavior displays a peak structure. In the presence of strong magnetic field, due to the Landau quantization of transverse motion of (anti-)quarks perpendicular to magnetic field, only the longitudinal Seebeck coefficient (S_{zz}) exists. Our results show that the value of S_{zz} at a fixed mu _{q} in the lowest Landau level (LLL) approximation always remains positive. Within the effect of high Landau levels, S_{zz} exhibits a thermal structure similar to that in the LLL approximation. As the Landau level increases further, S_{zz} decreases and even its sign changes from positive to negative. The computations of these thermoelectric transport coefficients are also extended to a medium with momentum-anisotropy induced by initial spatial expansion as well as strong magnetic field.

Nonlinear vibration, stability, and bifurcation analysis of axially moving and spinning cylindrical shells

The nonlinear vibration characteristics of the rotating axially moving circular cylindrical shells in subharmonic regions are investigated in the present paper. The motion equations are carried out based on the Hamilton principle in cylindrical coordinates utilizing Donnell’s nonlinear shell theory. By introducing the suitable airy stress function, three equilibrium equations in the cylindrical coordinates are simplified into two nonlinear coupled nonhomogeneous PDEs, including a compatibility equation and the transverse motion equation. The compatibility equation solution is obtained employing the seven degrees of freedom for the flexural mode shape of the system. By implementation of the Galerkin method, the motion equation would be projected into seven nonlinear coupled nonhomogeneous ODEs. This set of equations is solved using a direct normal form method validated by the numerical method and available data. The effect of angular velocity and axial speed is investigated employing frequency and force response curves, bifurcation diagrams, time history, and the system’s phase portraits. Always axially moving and rotation speed of the system intensifies the nonlinear behavior of the frequency responses.

Investigating the transverse motion of a pneumatic shock exciter using two different anvil mounting configurations

This paper describes novel design changes to the accelerometer mounting support of a commercial pneumatic shock exciter, with the aim of reducing the transverse motion the accelerometer is subjected to during shock excitation. The author describes the mounting support supplied by the manufacturer, the design changes made and the measurement data to compare the transfer motions recorded using two different mounting designs.

Time-Resolved PIV Measurements and Turbulence Characteristics of Flow Inside an Open-Cell Metal Foam.

Open-cell metal foams are porous medium for thermo-fluidic systems. However, their complex geometry makes it difficult to perform time-resolved (TR) measurements inside them. In this study, a TR particle image velocimetry (PIV) method is introduced for use inside open-cell metal foam structures. Stereolithography 3D printing methods and conventional post-processing methods cannot be applied to metal foam structures; therefore, PolyJet 3D printing and post-processing methods were employed to fabricate a transparent metal foam replica. The key to obtaining acceptable transparency in this method is the complete removal of the support material from the printing surfaces. The flow characteristics inside a 10-pore-per-inch (PPI) metal foam were analyzed in which porosity is 0.92 while laminar flow condition is applied to inlet. The flow inside the foam replica is randomly divided and combined by the interconnected pore network. Robust crosswise motion occurs inside foam with approximately 23% bulk speed. Strong influence on transverse motion by metal foam is evident. In addition, span-wise vorticity evolution is similar to the integral time length scale of the stream-wise center plane. The span-wise vorticity fluctuation through the foam arrangement is presented. It is believed that this turbulent characteristic is caused by the interaction of jets that have different flow directions inside the metal foam structure. The finite-time Lyapunov exponent method is employed to visualize the vortex ridges. Fluctuating attracting and repelling material lines are expected to enhance the heat and mass transfer. The results presented in this study could be useful for understanding the flow characteristics inside metal foams.

Comparison of two coupling methods regarding coupling patterns, sensitivity to footwear and potential future injury applications

Researchers have quantified the effect of footwear conditions on movement patterns and injury risk for runners using discrete kinematic variables and/or relative coupling variables. Coupling is typically assessed using the transfer coefficient (TC) or the vector coding (VC) approach. However, a thorough comparison of both methods regarding their interpretation, sensitivity to testing conditions and information regarding coupling strength as one overall coupling score is missing.This study aimed to compare both methods regarding a) their coupling patterns, b) their sensitivity to footwear conditions and c) to discuss both coupling approaches regarding an overall coupling score.3D motion capture data was collected of 10 males running on a treadmill with and without shoes. Rearfoot frontal and tibia transverse plane motion was analyzed. Discrete kinematic variables and relative coupling variables were calculated via the TC and VC approach for the landing and push-off phase. A novel variable, the coupling score, was developed and calculated using both coupling methods.Coupling variables calculated with both methods showed differences in coupling patterns, especially for the landing phase (TC ≈ 0.5/in-phase towards rearfoot-phase, VC ≈ 300°/anti-phase). VC offers further details, such as coupling frequencies, compared to the TC. Moreover, both methods were unable to distinguish between footwear conditions regarding their coupling patterns or coupling scores. Strong correlations (r ≤ 0.7, p < 0.0125) between coupling scores assessed with either method suggest that both methods contain similar information regarding coupling strength. The coupling score represents a first attempt to quantify a weighted coupling pattern quantitatively. Future studies have to validate whether the coupling score might be linked to injury risks.

Розрахунок оптимальних параметрів коректувальних елементів в індукційних системах прискорення

The formulations of a number of optimization problems for a linear induction acceleration system with respect to the adjustment parameters are considered. The dynamics of the transverse motion of electrons in the horizontal plane is investigated in the presence of given energy values for each resonator period: the particles at the initial moment of time are somewhat displaced relative to the accelerator axis (we neglect the displacements of the ends of the solenoids and the centers of the accelerating gaps relative to the accelerator axis). A connection is established between the initial and final coordinates and the components of the momentum. The presence of parasitic electric and magnetic fields arising as a result of the displacement of particles relative to the axis of the accelerator, which change the transverse components of the pulses, is taken into account. For the mathematical formulation of problems, in order to apply algorithms of practical stability, the original difference model of the induction system was converted to a linear form. By introducing into consideration the vector of parameters, the scatter of phase coordinates, and tolerances on the parameters, the problem of calculating the tolerances for given linear constraints on the scatter of phase coordinates for the corresponding inhomogeneous system is formulated. For the case of nonlinear dynamic constraints on the spread of the vector of phase coordinates, it is proposed to approximate a convex closed set by tangent hyperplanes. Numerical estimation of the range of tolerances for the parameters of correcting elements is reduced to the problems of practical stability of discrete parametric systems. In this case, the region of the initial conditions on the state vector, the tolerances on the parameters, are given structurally in the form of an ellipsoid, which makes it possible to numerically solve the original problem as an extremal one. From the standpoint of practical stability in the corresponding space of functions, the problem of assessing the range of tolerances for the parameters of correcting elements in the presence of specified restrictions on the spread of the quality criterion is considered. Attention is focused on an important class of problems of numerical modelling of a linear induction acceleration system − problems of practical stability. Numerical estimation of the region of initial displacements of the transverse coordinates of the linear induction acceleration system in the given structures in the presence of linear constraints on the vector of phase coordinates in dynamics is carried out. Key words: modeling, induction system of acceleration, solenoid, parameters, elements of correction, optimization, stability

Three-dimensional nonlinear extreme vibrations of cantilevers based on a geometrically exact model

In this paper, a three-dimensional geometrically exact model is developed for cantilevers, for the first time, which allows for accurate analysis of oscillations of extremely large amplitude. The proposed exact model is on the basis of three Euler angles describing the centreline motion. Euler–Bernoulli beam theory is utilised together with Kelvin–Voigt material damping, while utilising the centreline-inextensibility assumption. Hamilton’s principle is utilised to derive the equations of motion for the three rotational motions, while keeping all terms geometrically exact. Galerkin discretisation is performed on the three partial differential equations of motion and the resultant set of discretised equations is solved using a continuation technique. The unique feature of the proposed exact model is its capability to capture very large-amplitude vibrations accurately, for both two-dimensional and three-dimensional motions. The dynamical response of the cantilever is examined in detail in the primary resonance region, highlighting the effect of the one-to-one internal resonance between the in-plane and out-of-plane transverse motions. A comparison between the geometrically exact model and the third-order nonlinear model is conducted to better showcase the significance of the proposed exact model, and the limitations of a truncated third-order model.

General Relativistic Aberration Equation and Measurable Angle of Light Ray in Kerr–de Sitter Spacetime

As an extension of our previous paper, instead of the total deflection angle α, we will mainly focus on the discussion of measurable angle of the light ray ψP at the position of observer P in Kerr–de Sitter spacetime, which includes the cosmological constant Λ. We will investigate the contribution of the radial and transverse motion of the observer which are connected with radial velocity vr and transverse velocity bvϕ (b is the impact parameter) as well as the spin parameter a of the central object which induces the gravito-magnetic field or frame dragging and the cosmological constant Λ. The general relativistic aberration equation is employed to take into account the influence of motion of the observer on the measurable angle ψP. The measurable angle ψP derived in this paper can be applicable to the observer placed within the curved and finite-distance region in the spacetime. The equation of light trajectory will be obtained in such a sense that the background is de Sitter spacetime instead of Minkowski one. As an example, supposing the cosmological gravitational lensing effect, we assume that the lens object is the typical galaxy and the observer is in motion with respect to the lensing object at a recession velocity vr=bvϕ=vH=H0D (where H0 is a Hubble constant and D means the distance between the observer and the lens object). The static terms O(Λbm,Λba) are basically comparable with the second order deflection term O(m2), and they are almost one order smaller that the Kerr deflection −4ma/b2. The velocity-dependent terms O(Λbmvr,Λbavr) for radial motion and O(Λb2mvϕ,Λb2avϕ) for transverse motion are at most two orders of magnitude smaller than the second order deflection O(m2). We also find that even when the radial and transverse velocity have the same sign, asymptotic behavior as ϕ approaches 0 is different from each other, and each diverges to opposite infinity.

Random walk of antiferromagnetic skyrmions in granular films

The impressive absence of the skyrmion Hall effect of antiferromagnetic (AFM) skyrmions in clean systems has raised high expectations of AFM skyrmions as information carriers and the potential applications in data storage technology. Here, we report an undesired behavior of current-driven AFM skyrmion dynamics in granular thin films. Understanding the motion of AFM skyrmions in disordered systems is crucial because disorders are inevitable in all materials. Micromagnetic simulations show that AFM skyrmions deviate from their trajectory in the clean limit. Interestingly, the transverse (to the current direction) motion is diffusive, i.e., the mean square of transverse displacement is proportional to the traveling time. The longitudinal (along with the current direction) motion is always hindered by disorders. An effective theory based on the stochastic Thiele equation can account for the observed phenomena. At a very strong disorder above a critical value that depends on the current density, AFM skyrmions are pinned. Our findings should be important for future spintronic devices based on AFM skyrmions.

Assisted Spatial Sit-to-Stand Prediction—Part 2: Virtual Injured Elderly Individuals

Abstract Sit-to-stand (STS) is a challenging task, especially for injured elderly in their daily life. This paper presents Part 2 of the assisted spatial STS computational motion prediction to investigate the effect of a unilateral grab-rail bar placed on the right-hand side on STS motion performance for injured virtual individuals (computational digital human model-DHM) with either right or left knee injury. The motion prediction formulation was constructed as a nonlinear optimization and validated in Part 1 of the assisted spatial STS motion prediction (Yang, J., and Ozsoy, B., 2021, “Assisted Spatial Sit-to-Stand Prediction—Part 1: VirtualHealthy Elderly Individuals,” ASME J. Comput. Inf. Sci. Eng., 21(4), p. 041002). Injuries are implemented into the formulation with reduction rates of 75% in a single knee‘s extension torque limits. Two different objective functions are tested: The first one is just minimizing the dynamic effort where the second one is minimizing the difference between right and left side support reaction forces in addition to the dynamic effort. Computational simulations resulted in that systematic changes are seen in the joint coordination better with the first objective function for the elderly group with either right or left knee injury. Since only one of the knees is modeled to experience a strength loss, virtual-individuals tend to flex their trunk to the intact side whilst rotating the upper-body to the right side with both objective functions due to holding the grab-rail bar, which was placed to the right side of the biomechanical model. Based on the peak values of the center of mass velocity and displacement profiles in both the medial-lateral axis, virtual-individuals prefer to use lateral plane motions less and transverse plane motions more to minimize the difference between right and left side-vertical support reaction forces with the second objective function.

NUMERICAL SIMULATION ON A DEEP-DRAFT SEMI-SUBMERSIBLE

A numerical study is conducted to determine the Vortex Induced Motion (VIM) effects on Deep-Draft Semi-Submersibles (DDSS). The VIM phenomena is a crucial problem that can cause severe impact on the fatigue life of mooring risers in DDSS. Therefore, a comprehensive numerical simulation is conducted using the Acusolve computational fluid dynamics (CFD) software. Five models of immersed columns with different aspect ratios (ie. 0.6, 0.8, 1.0, 1.2 and 1.4) are numerically investigated under two different incidence angles, which are 0° and 45°. The transverse and in-line vibration amplitude, amplitude of lift force coefficient and vortex shedding are analyzed. The numerical measurements are obtained to see the response of horizontal plane motions, which are transverse, in line and yaw motions. This study with detailed numerical results from parametric data will contribute future studies and the comparisons are made to demonstrate the capability of the present CFD approach.