Fine-Tuning Geometrically Constrained Planar Motions

2011 ◽  
Author(s):  
Ping Zhao ◽  
Q. J. Ge ◽  
Feng Gao ◽  
Hai-Jun Su
Keyword(s):  
Standard Deviation ◽  
Kinetic Energy ◽  
Reference Frames ◽  
Distance Measure ◽  
Fine Tuning ◽  
Planar Motion ◽  
Motion Error ◽  
Point Trajectories ◽  
Geometrically Constrained ◽  
Planar Motions

This paper presents a method for fine-tuning a geometrically constrained planar motion in the context of motion approximation. It builds on the recent work that seeks to identify and extract point trajectories of an explicitly given planar motion. Once two point trajectories are obtained, the remaining issue is to determine the length of the “coupler link” that connects the two point trajectories such that the resulting motion best approximates the original motion. In this paper, the concept of standard deviation in statistics and probability theory is used to define the “distance” between two planar motions. This distance definition is bi-invariant with respect to the choice of both moving and fixed reference frames. Furthermore, the concept of kinetic energy is also used for combining translation with rotation when calculating the distance between two planar displacements. A simple, direct search method for obtaining the optimum length of the coupler link is presented that minimizes the standard deviation of the motion error in terms of the kinetic energy based distance measure for planar displacements.

scholarly journals Fine Tuning a Bile-Enzymatic-Gravimetric Total Dietary Fiber Method

1997 ◽  
Vol 80 (1) ◽  
pp. 89-94 ◽  
Author(s):  
Kenneth J Cranker ◽  
Katherine M Phillips ◽  
Maria Carmen Rita V Gonzales ◽  
Kent K Stewart
Keyword(s):  
Standard Deviation ◽  
Dietary Fiber ◽  
Collaborative Study ◽  
Original Method ◽  
Fine Tuning ◽  
Official Method ◽  
Total Dietary Fiber ◽  
Modified Method ◽  
Relative Standard ◽  
Wet Weight

Abstract A recently proposed bile-enzymatic-gravimetric total dietary fiber (TDF) method was modified and the new procedure was compared with the original method, the traditional AOAC enzymatic-gravimetric determination (AOAC Official Method 985.29), and another simplified AOAC procedure by analyzing several diet composites, including National Institute of Standards and Technology 1548 total diet reference material. The original and modified bile-enzymatic-gravimetric procedures also were compared by analyzing 9 food samples from a collaborative study of the original method. The modified method consistently yielded values about 10% lower than the original method but closer to reference values and to values from AOAC Offical Method 985.29, suggesting results that are more in line with accepted TDF standard methodology. Our modified method was used to analyze 180 fresh-frozen diet composites with TDF values ranging from 0.6 to 3.2 g/100 g wet weight. Samples were from 2 multicenter feeding studies sponsored by the National Heart, Lung and Blood Institute: DELTA (Dietary Effects on Lipoproteins and Thrombogenic Activity) and DASH (Dietary Approaches to Stop Hypertension). The mean relative standard deviation (RSD) for duplicate analyses was 1.1%. For 40 assays of a quality control diet composite over 9 months, the standard deviation was 0.1 g/100 g wet weight (4.9% RSD), indicating the method’s excellent precision for routine use.

Context Inference Engine (CiE)

2012 ◽  
Vol 4 (3) ◽  
pp. 13-41 ◽  
Author(s):  
Umar Mahmud ◽  
Mohammed Younus Javed
Keyword(s):  
Standard Deviation ◽  
Context Awareness ◽  
Distance Measure ◽  
Inference Engine ◽  
General Context ◽  
Context Aware ◽  
Contextual Data ◽  
Classification Approach ◽  
Current Context ◽  
Context Aware System

Context Awareness is the task of inferring contextual data acquired through sensors present in the environment. ‘Context’ encompasses all knowledge bounded by a scope and includes attributes of machines and users. A general context aware system is composed of context gathering and context inference modules. This paper proposes a Context Inference Engine (CiE) that classifies the current context as one of several recorded context activities. The engine follows a distance measure based classification approach with standard deviation based ranks to identify likely activities. The paper presents the algorithm and some results of the context classification process.

Fine Tuning of Rational B-Splines Motions

1997 ◽  
Author(s):  
Lakshmi N. Srinivasan ◽  
Q. Jeffrey Ge
Keyword(s):  
Kinetic Energy ◽  
Computer Aided Design ◽  
Rate Of Change ◽  
Image Space ◽  
Fine Tuning ◽  
Smoothing Algorithm ◽  
B Spline ◽  
Spline Curves ◽  
Aided Design ◽  
Spatial Kinematics

Abstract This paper presents two algorithms for fine-tuning rational spatial motions suitable for Computer Aided Design. The rational motions are represented by rational B-spline curves in a projective dual three-space known as the Image Space of Spatial Kinematics. The problem of fine-tuning of rational motions is studied as that of fine-tuning the corresponding rational curves in the Image Space called the image curves. The path-smoothing algorithm automatically detects and smoothes out the third order geometric discontinuities in the path of a cubic rational Bspline image curve. The speed-smoothing algorithm uses a quintic rational spline image curve to obtain a second-order geometric approximation of the path of a cubic rational B-spline image curve while allowing specification of the speed and the rate of change of speed at the key points to obtain a near constant kinetic energy parametrization. The notion of kinetic energy is used in the paper as a natural way of combining the rotational and translational speed of a spatial motion. The results have applications in trajectory generation in robotics, planing of camera movement, spatial navigation in visualization and virtual reality systems, as well as mechanical system simulation.

On the modified Circumpolar Deep Water upwelling over the Four Ladies Bank in Prydz Bay, East Antarctica

2020 ◽  
Author(s):  
Chengyan Liu ◽  
Zhaomin Wang ◽  
Chen Cheng ◽  
Xi Liang ◽  
Yang Wu ◽  
...  
Keyword(s):  
Heat Flux ◽  
Standard Deviation ◽  
Kinetic Energy ◽  
Potential Temperature ◽  
Weddell Sea ◽  
East Antarctica ◽  
Prydz Bay ◽  
Ice Shelf ◽  
Borehole Data ◽  
Amery Ice Shelf

<p>We report on mooring observations of tidal currents in Prydz Bay, East Antarctica. Tides in Prydz Bay are mixed diurnal-semidiurnal and much weaker than that in the Ross Sea and the Weddell Sea, with the spatial and temporal averaged value of 2.58 cm s<sup>-1</sup> for all the current meter observations over the continental shelf. The major axes of the tidal ellipses are generally aligned south-north, probably steered by the topography. The tidal phases are modulated by both the baroclinic and barotropic tidal components. The averaged tidal kinetic energy can account for a fraction of ~13% with respect to the total kinetic energy at the Amery Ice Shelf calving front during the observing period. The long-term average tidal heat flux across the Amery Ice Shelf calving front is negligible, but the ratio of the tidal heat flux standard deviation to the residual heat flux standard deviation can be up to 41%. We also report on borehole observations of tide-like pulsing of potential temperature and salinity, indicating the indispensable tidal influences in the ice-ocean boundary layer. These mooring and borehole data support that the tidal processes should be highlighted in the investigations of the interaction between the Amery Ice Shelf and ocean.</p>

Bobillier Formula for One Parameter Motions in the Complex Plane

2012 ◽  
Vol 4 (2) ◽  
Author(s):  
Soley Ersoy ◽  
Nurten Bayrak
Keyword(s):  
Complex Plane ◽  
Complex Number ◽  
Second Order ◽  
Geometrical Interpretation ◽  
Planar Motion ◽  
Radius Of Curvature ◽  
Fundamental Law ◽  
Planar Motions

This is a brief note expanding on the aspect of Fayet (2002, “Bobillier Formula as a Fundamental Law in Planar Motion,” Z. Angew. Math. Mech., 82(3), pp. 207–210), which investigates the Bobillier formula by considering the properties up to the second order planar motion. In this note, the complex number forms of the Euler Savary formula for the radius of curvature of the trajectory of a point in the moving complex plane during one parameter planar motion are taken into consideration and using the geometrical interpretation of the Euler Savary formula, Bobillier formula is established for one parameter planar motions in the complex plane. Moreover, a direct way is chosen to obtain Bobillier formula without using the Euler Savary formula in the complex plane. As a consequence, the Euler Savary given in the complex plane will appear as a particular case of Bobillier formula.

scholarly journals HETEROGENEITY MEASUREMENT BASED ON DISTANCE MEASURE FOR POLARIMETRIC SAR DATA

2018 ◽  
Vol IV-3 ◽  
pp. 233-237
Author(s):  
Xiaoli Xing ◽  
Qihao Chen ◽  
Xiuguo Liu
Keyword(s):  
Standard Deviation ◽  
Synthetic Aperture Radar ◽  
Covariance Matrix ◽  
Distance Measure ◽  
Synthetic Aperture ◽  
Polarimetric Sar ◽  
Polarimetric Synthetic Aperture Radar ◽  
Local Window ◽  
The Mean ◽  
Sar Data

To effectively test the scene heterogeneity for polarimetric synthetic aperture radar (PolSAR) data, in this paper, the distance measure is introduced by utilizing the similarity between the sample and pixels. Moreover, given the influence of the distribution and modeling texture, the K distance measure is deduced according to the Wishart distance measure. Specifically, the average of the pixels in the local window replaces the class center coherency or covariance matrix. The Wishart and K distance measure are calculated between the average matrix and the pixels. Then, the ratio of the standard deviation to the mean is established for the Wishart and K distance measure, and the two features are defined and applied to reflect the complexity of the scene. The proposed heterogeneity measure is proceeded by integrating the two features using the Pauli basis. The experiments conducted on the single–look and multilook PolSAR data demonstrate the effectiveness of the proposed method for the detection of the scene heterogeneity.

scholarly journals Patrones de desplazamiento del eje instantáneo de rotación del movimiento de elevación humeral

2019 ◽  
Author(s):  
Álvaro Felipe Page ◽  
Magda Liliana Cáceres Cáceres
Keyword(s):  
Degree Of Freedom ◽  
Planar Motion ◽  
Helical Axis ◽  
Optimal Average ◽  
Planar Motions

En este trabajo se presentan los resultados de un estudio experimental para la descripción de las trayectorias descritas por el eje instantáneo de rotación (EIR) toracohumeral para movimientos cíclicos de elevación-descenso. Se ha desarrollado una técnica de análisis de movimientos mediante videofotogrametría que permite la medida del EIR del movimiento relativo húmero tórax con un error inferior a 1 cm y de forma muy reproducible [1,2]. Esto permite registrar el movimiento continuo del EIR como un axoide, cuyo desplazamiento mediolateral está relacionado con las velocidades de rotación de las articulaciones esternoclavicular, acromioclavicular y glenohumeral, y cuya posición vertical se asocia a la elevación de articulación glenohumeral [3] Se ha realizado un estudio con 45 sujetos sanos y 15 sujetos con patologías del hombro, analizando el movimiento cíclico de elevación-descenso del húmero en los planos frontal y escapular. La ubicación y forma de los axoides es sensible a los efectos de la carga y del estado funcional del sujeto. Así el efecto de la carga se manifiesta en un desplazamiento medial de la trayectoria del EIR, asociado a un movimiento más acusado de las articulaciones esternoclavicular, acromioclavicular frente al movimiento sin carga. Por otra parte, el efecto de la patología afecta a la trayectoria del EIR sólo a partir de cierto nivel de limitación funcional. Los patrones correspondientes a pacientes con limitaciones leves no muestran diferencias importantes frente a los sujetos sanos. Los resultados obtenidos muestran que el EIR puede ser de utilidad en la valoración funcional biomecánica del hombro, al ofrecer información sobre la coordinación de las diferentes articulaciones que lo constituyen REFERENCIAS [1]  A.Page, J.A. Gálvez, H. de Rosario, V. Mata., J. Prat. Optimal average path of the instantaneous shelical axis in planar motions with one functional degree of freedom. Jnl. Biomech, vol. 43, pp 375-378, 2010. doi: 10.1016/j.jbiomech.2009.09.023. [2]  A.Page, H. de Rosario, J.A. Gálvez, V. Mata. Representation of planar motion of complex joints by means of rolling pairs. Application to neck motion. Jnl. Biomech, vol. 44, pp 747-750, 2011. doi: 10.1016/j.jbiomech.2010.11.019. [3]  M. Cáceres, P. Serra, J. Lopez, & A. Page. Reliability of the Shoulder Instantaneous Helical Axis measurement during the scaption movement. Gait & Posture, vol. 49, pp 268, 2016.

scholarly journals Influencia de la emisión de neutrones en la medición por el método de la doble energía de la distribución de masa y energía cinética de los fragmentos de la fisión espontánea del 252Cf

2019 ◽  
pp. 15-19
Keyword(s):  
Monte Carlo ◽  
Standard Deviation ◽  
Monte Carlo Method ◽  
Kinetic Energy ◽  
Energy Distribution ◽  
Energy Method ◽  
Spontaneous Fission ◽  
Neutron Emission ◽  
Mass Energy ◽  
San Marcos

Influencia de la emisión de neutrones en la medición por el método de la doble energía de la distribución de masa y energía cinética de los fragmentos de la fisión espontánea del 252Cf Influence of neutron emission on the measurement by double-energy method of mass and kinetic energy distribution of the fragments from spontaneous fission of 252Cf Modesto Montoya, Carlos Romero y Justo Rojas Instituto Peruano de Energía Nuclear Universidad Nacional de Ingeniería, Av. Túpac Amaru 210, Rímac, Lima Universidad Nacional Mayor de San Marcos, Av. Venezuela, s/n, Callao DOI: https://doi.org/10.33017/RevECIPeru2011.0003/ RESUMEN El método de doble energía ha sido usado por varios autores para medir la distribución de masa (A*) y energía cinética total de los fragmentos complementarios (EKT*) de la fisión espontánea del 252Cf, encontrándose un ensanchamiento de la desviación estándar de distribución de EKT* (σEKT*) en la región cercana a la simetría de masas (A* = 226). Usando el método Monte Carlo, nosotros mostramos que ese ensanchamiento se debe que para cada valor de A* se produce la superposición de distribuciones de EKT* correspondientes a fragmentos primarios con dos o más masas vecinas, respectivamente. Descriptores: fision espontánea, 252Cf, fragmentos distribución masa energía. ABSTRACT The double energy method has been used by several authors to measure the mass (A *) and total kinetic energy (EKT *) distribution of the complementary fragments from spontaneous fission of 252Cf, finding an broadening of the distribution standard deviation EKT * (σEKT *) in the region near mass symmetry (A * = 226). Using Monte Carlo method, we show that this broadening is because for each value of A * an overlapping of distributions EKT * for primary fragments with two or more neighboring masses, respectively, are produced. Keywords: spontaneous fission 252Cf, fragments distribution mass energy.

scholarly journals Alumina-Based Ceramics for Armor Application: Mechanical Characterization and Ballistic Testing

2014 ◽  
Vol 2014 ◽  
pp. 1-6 ◽  
Author(s):  
M. V. Silva ◽  
D. Stainer ◽  
H. A. Al-Qureshi ◽  
O. R. K. Montedo ◽  
D. Hotza
Keyword(s):  
Standard Deviation ◽  
Kinetic Energy ◽  
Mechanical Characterization ◽  
Industrial Plant ◽  
Metallic Plate ◽  
Thick Plates ◽  
Lower Standard ◽  
Aisi 1045 ◽  
Ballistic Test ◽  
Ballistic Testing

The aim of this work is to present results of mechanical characterization and ballistic test of alumina-based armor plates. Three compositions (92, 96, and 99 wt% Al2O3) were tested for 10 mm thick plates processed in an industrial plant. Samples were pressed at 110 MPa and sintered at 1600°C for 6 h. Relative density, Vickers hardness, and four-point flexural strength measurements of samples after sintering were performed. Results showed that the strength values ranged from 210 to 300 MPa depending on the porosity, with lower standard deviation for the 92 wt% Al2O3 sample. Plates (120 mm × 120 mm × 12 mm) of this composition were selected for ballistic testing according to AISI 1045, using a metallic plate as backing and witness plates in the case of penetration or deformation. Standard NIJ-0108.01 was followed in regard to the type of projectile to be used (7.62 × 51 AP, Level IV, 4068 J). Five alumina plates were used in the ballistic tests (one shot per plate). None of the five shots penetrated or even deformed the metal sheet, showing that the composition containing 92 wt% Al2O3 could be considered to be a potential ballistic ceramic, being able to withstand impacts with more than 4000 J of kinetic energy.

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