Wheelchair-Portable Patient Lift

2018 ◽  
Vol 13 (1) ◽  
Author(s):  
Yoshikazu Mori ◽  
Akihiko Nakada
Keyword(s):  
Nursing Home ◽  
Flat Surface ◽  
Center Of Mass ◽  
Experimental Results ◽  
Assistive Device ◽  
Leaving Home ◽  
Sliding Mechanism ◽  
Small Force ◽  
Weight Carrying ◽  
Sufficient Strength

A patient lift is an assistive device for patients who lack sufficient strength or muscle control to be transferred between a wheelchair and a toilet or other places. Patient lifts of two kinds are commonly used: overhead lifts and mobile lifts. Nevertheless, because of its size and weight, carrying even a mobile lift with a wheelchair is difficult when leaving home. This study examined a novel portable patient lift that is small and light, sufficient to be carried using a wheelchair in a folded state. It is compact, light, and portable because it has no actuator. Moreover, its operation is simple. It is useful not only at home or in a nursing home but on any flat surface during daily excursions and activities, even in a conventional lavatory. A caregiver can transfer a user with a small force because this lift has a sliding mechanism that brings the fulcrum closer to the patient's center of mass. Experimental results underscore the effectiveness of the proposed patient lift.

Extended validation of a ground-based three-axis spacecraft simulator model

2020 ◽  
pp. 095441002093896
Author(s):  
H Sh Ousaloo ◽  
Gh Sharifi ◽  
B Akbarinia
Keyword(s):  
Mathematical Model ◽  
Attitude Control ◽  
Aerodynamic Drag ◽  
Center Of Mass ◽  
Model Development ◽  
Optimization Method ◽  
Experimental Results ◽  
Spacecraft Dynamics ◽  
Detailed Model ◽  
Mass Properties

The ground-based spacecraft dynamics simulator plays an important role in the implementation and validation of attitude control scenarios before a mission. The development of a comprehensive mathematical model of the platform is one of the indispensable and challenging steps during the control design process. A precise mathematical model should include mass properties, disturbances forces, mathematical models of actuators and uncertainties. This paper presents an approach for synthesizing a set of trajectories scenarios to estimate the platform inertia tensor, center of mass and aerodynamic drag coefficients. Reaction wheel drag torque is also estimated for having better performance. In order to verify the estimation techniques, a dynamics model of the satellite simulator using MATLAB software was developed, and the problem reduces to a parameter estimation problem to match the experimental results obtained from the simulator using a classical Lenevnberg-Marquardt optimization method. The process of parameter identification and mathematical model development has implemented on a three-axis spherical satellite simulator using air bearing, and several experiments are performed to validate the results. For validation of the simulator model, the model and experimental results must be carefully matched. The experimental results demonstrate that step-by-step implementation of this scenario leads to a detailed model of the platform which can be employed to design and develop control algorithms.

Robust Multibit Image Watermarking Based on Contrast Modulation and Affine Rectification

2019 ◽  
Vol 33 (14) ◽  
pp. 1954036
Author(s):  
Xin Zhong ◽  
Frank Y. Shih
Keyword(s):  
Image Processing ◽  
Lower Bound ◽  
State Of The Art ◽  
Image Watermarking ◽  
Center Of Mass ◽  
Experimental Results ◽  
Superior Performance ◽  
The Common ◽  
Distortion Parameters ◽  
Watermarking Scheme

In this paper, we present a robust multibit image watermarking scheme to undertake the common image-processing attacks as well as affine distortions. This scheme combines contrast modulation and effective synchronization for large payload and high robustness. We analyze the robustness, payload, and the lower bound of fidelity. Regarding watermark resynchronization under affine distortions, we develop a self-referencing rectification method to detect the distortion parameters for reconstruction by the center of mass in affine covariant regions. The effectiveness and advantages of the proposed scheme are confirmed by experimental results, which show the superior performance as comparing against several state-of-the-art watermarking methods.

Experimental and empirical study of large transverse deformation of triangular plates subjected to water hammer shock loading

2019 ◽  
Vol 233 (12) ◽  
pp. 2498-2509
Author(s):  
Mojtaba Haghgoo ◽  
Mohammad Rezasefat ◽  
Ali Mahmoudi ◽  
Hashem Babaei
Keyword(s):  
Mechanical Properties ◽  
Center Of Mass ◽  
Experimental Tests ◽  
Experimental Results ◽  
Dimensionless Numbers ◽  
Hydrodynamic Loads ◽  
Drop Hammer ◽  
Properties Of Materials ◽  
Plate Geometry ◽  
Insight Into

In this paper, the dynamic plastic response of isosceles triangular plates under hydrodynamic loads was investigated experimentally using a drop hammer machine. To do this, a series of experimental tests were carried out on mild steel triangular plates with different thicknesses to bring insight into the effect of geometry and mechanical properties of the plate on the deformation of specimens, which were impacted by a piston-induced pressure wave inside a water tube. The effects of various impact loads originated from different drop hammer standoff distances, and hammer weights concerning variations of deflection of the center of mass were described. The experimental results were presented in terms of deflection of the center of mass of the plates and deflection profiles. The experimental results showed that the plate with lower thickness experienced higher deflection-to-thickness ratio. An empirical model was also proposed based on new dimensionless numbers for triangular plates in order to predict the ratio of deflection of the center of mass to thickness. The dimensionless numbers considered the effects of plate geometry, hydrodynamic applied load, and mechanical properties of materials. Comparison between the experimental results and empirical predictions demonstrated that the suggested model is accurate enough to predict of the response of isosceles triangular plates under hydrodynamic loads.

scholarly journals HANBURY-BROWN–TWISS INTERFEROMETRY WITH IDENTICAL BOSONS IN RELATIVISTIC HEAVY ION COLLISIONS: COMPARISONS WITH HADRONIC SCATTERING MODELS

2006 ◽  
Vol 15 (01) ◽  
pp. 197-236 ◽  
Author(s):  
THOMAS J. HUMANIC
Keyword(s):  
Heavy Ion Collisions ◽  
Center Of Mass ◽  
Heavy Ion ◽  
Physical Significance ◽  
Experimental Results ◽  
Relativistic Heavy Ion Collisions ◽  
Identical Boson ◽  
Ion Collisions

Identical boson Hanbury-Brown–Twiss interferometry as applied to relativistic heavy-ion collisions is reviewed. Emphasis is placed on the use of hadronic scattering models to interpret the physical significance of experimental results. Interferometric studies with center-of-mass energies from <1 GeV/nucleon up to 5500 GeV/nucleon are considered.

ANTI-PROTON TO PROTON RATIOS FROM Au + Au COLLISIONS AT $\sqrt{s_{NN}}=200~{\rm GeV}$ BY RQMD

2003 ◽  
Vol 18 (16) ◽  
pp. 1107-1112
Author(s):  
YUNHUA CHENG ◽  
FENG LIU
Keyword(s):  
Transverse Momentum ◽  
Center Of Mass ◽  
Experimental Results ◽  
Mass Energy ◽  
Center Of Mass Energy

Events of Au + Au collisions from AGS to RHIC energies by RQMD (v2.4) generator are produced. [Formula: see text] ratios as functions of rapidity, transverse momentum and centrality at [Formula: see text] are studied. The dependence on the center of mass energy of [Formula: see text] ratios is presented, compared with the experimental results. It is shown that [Formula: see text] ratio from rescattering RQMD is lower than those of the experiments at RHIC energies. We argue that hadronic rescattering at RHIC energies is suppressed compared to AGS, SPS energies.

Design of a Gravity-Balanced Assistive Device for Sit-to-Stand Tasks

2004 ◽  
Author(s):  
Abbas Fattah ◽  
Sunil K. Agrawal ◽  
John Fitzgibbons
Keyword(s):  
Center Of Mass ◽  
The Elderly ◽  
Joint Torque ◽  
Assistive Device ◽  
Inverse Dynamic ◽  
Joint Torques ◽  
Gravitational Torque ◽  
Total Potential ◽  
Cord Injury ◽  
Standing Up

The joint torques in hip, knee and ankle are computed using inverse dynamic model during standing up for a paraplegic patient. The joint torque comprises the dynamical torque due to the inertia forces, and a passive torque due to the muscles and gravitational torque. It has been observed that the contribution to the joint torques by the gravitational torque is dominant. On the basis of this result, a gravity balanced assistive device is proposed for the elderly and impaired people such as spinal cord injury and paraplegic patients. This passive device uses a hybrid method to identify the center of mass of the system using auxiliary parallelograms first. Next appropriate springs are connected to the device to vanish the total potential energy of the system due to the gravity during standing up. A prototype with the underlying principles is currently being fabricated at the University of Delaware.

Optimal Design of a Pulsed Water Jet Nozzle

1995 ◽  
Author(s):  
Zheng Li ◽  
E. S. Geskin
Keyword(s):  
Material Removal ◽  
Flat Surface ◽  
Water Jet ◽  
Experimental Results ◽  
Optimal Angle ◽  
Jet Nozzle ◽  
Pulsed Water Jet ◽  
The One ◽  
Pulsating Water Jet ◽  
Better Than

Abstract The objective of this paper is to evaluate the effect of the geometry of downstream edge in the resonating cavity on the performance of a pulsating water jet nozzle. The operation of this nozzle is evaluated by numerical modeling of the water flow within the nozzle. A procedure of computer simulation is employed to examine the performance of the nozzle and the numerical simulation results are validated by the experiments. The nozzle is formed by the use of two conventional nozzles connected by a cavity and numerical and experimental results show that the downstream edge in the cavity has an important effect on the performance of the nozzle. The obtained information demonstrate that the downstream edge with geometry of concave shape is better than the one of convex and flat surface due to its convergent shape enhancing the focusing of the jet and thus increasing the jet kinetic energy. The numerical and experimental results show that the optimal angle of downstream edge is 75° for the best operation of the nozzle. The substantial increase of the rate of cleaning and erosion of such as aluminum, steel and titanium in the course of use of optimal designed nozzle is observed. The obtained computational results enable us to design an effective nozzle suitable for both material removal and surface processing.

Large heteromorph ammonites from the Upper Cretaceous of Seymour Island, Antarctica

1989 ◽  
Vol 63 (5) ◽  
pp. 626-636 ◽  
Author(s):  
Eduardo B. Olivero ◽  
William J. Zinsmeister
Keyword(s):  
Upper Cretaceous ◽  
Flat Surface ◽  
Center Of Mass ◽  
The Body ◽  
Total Density ◽  
Nacreous Layer ◽  
Shell Wall ◽  
Body Chamber ◽  
Large Size ◽  
Seymour Island

Two species of the heteromorph ammonite genus Diplomoceras Hyatt are described from the Upper Cretaceous of the James Ross–Seymour Islands area, Antarctica. The late Campanian–early Maastrichtian D. lambi Spath has a relatively high rib density, whereas D. maximum n. sp. has a lower rib density and is known only from the uppermost Maastrichtian of the Lopez de Bertodano Formation on Seymour Island. Both species attain an exceptionally large size with the body chamber of D. maximum n. sp. attaining a length in excess of one meter. The structure of the shell wall in Diplomoceras is characterized by the thickening of the nacreous layer below the ribs. The shell thickening results in an inner flat surface and a smooth phragmocone. Reconstruction of the shell suggests at least four parallel shafts and three U-connectives. Estimates of the total density, center of buoyancy, and center of mass in this reconstructed shell indicate a slightly positive buoyant shell with a relatively unstable floating position.

The Null Dynamical Effect, and Some Frequency Spectra, of Resonant Inertial Pressure Waves in a Rapidly Rotating, Right Circular, Sectored Cylinder

1980 ◽  
Vol 47 (3) ◽  
pp. 475-481
Author(s):  
W. E. Scott
Keyword(s):  
Rigid Body ◽  
Small Amplitude ◽  
Incompressible Liquid ◽  
Reasonable Agreement ◽  
Center Of Mass ◽  
Experimental Results ◽  
Pressure Waves ◽  
Frequency Spectra ◽  
Gyroscopic Motion ◽  
Amplitude Growth

It is shown that inertial waves in the form of standing asymmetrical pressure waves can exist in an incompressible liquid in a rotating sectored cylinder in a rigid body (e.g., a top or a missile) executing a small amplitude gyroscopic motion about its center of mass. Some of the frequency spectra of these waves are presented along with the result that sectoring the cylinder into any number of equal sectors results in eliminating the destabilizing effect of these waves (i.e., the amplitude growth of the motion of the rigid container) when there is a “Stewartson” resonance between the frequency of one of the inertial modes and the frequency of the nutational component of the motion of the container. Experimental results are in reasonable agreement with the theory.

Sign in / Sign up

Export Citation Format

Share Document