077 Bezier-spline curves to describe the paediatric airway: a proof of concept project

2018 ◽  
Author(s):  
C Morrison ◽  
J Roberts ◽  
D Adams ◽  
M Miquel ◽  
P Cunnington
Author(s):  
Yasong Pu ◽  
Yaoyao Shi ◽  
Xiaojun Lin ◽  
Jian Guo

Smooth orientation planning has an important influence on the working quality and service life as for industrial robot. Based on the logarithmic quaternion, a compact method to map a spline curve from Cartesian space to quaternion space is proposed, and consequently the multi-orientation smooth interpolation of quaternion is realized. Combining with the relevant example case, the detailed method and steps of multi-orientation interpolation are introduced for mapping Hermite spline curve into quaternion space, and the validity of the principle is verified by using the example case. The present multi-orientation smooth interpolation of quaternion has the characteristics of simple construction, easy implementation and intuitive understanding. The method is not only applicable to multi-orientation interpolation of quaternion with Hermite spline curve, but also can extended to the spline curves such as Bezier spline and B-spline.


Mathematics ◽  
2020 ◽  
Vol 9 (1) ◽  
pp. 47
Author(s):  
Konstantin Panchuk ◽  
Tatyana Myasoedova ◽  
Evgeniy Lyubchinov

This paper is dedicated to development of mathematical models for polynomial spline curve formation given extreme vector derivatives. This theoretical problem is raised in the view of a wide variety of theoretical and practical problems considering motion of physical objects along certain trajectories with predetermined laws of variation of speed, acceleration, jerk, etc. The analysis of the existing body of work on computational geometry performed by the authors did not reveal any systematic research in mathematical model development dedicated to solution of similar tasks. The established purpose of the research is therefore to develop mathematical models of formation of spline curves based on polynomials of various orders modeling the determined trajectories. The paper presents mathematical models of spline curve formation given extreme derivatives of the initial orders. The paper considers construction of Hermite and Bézier spline curves of various orders consisting of various segments. The acquired mathematical models are generalized for the cases of vector derivatives of higher orders. The presented models are of systematic nature and are universal, i.e., they can be applied in formation of any polynomial spline curves given extreme vector derivatives. The paper provides a number of examples validating the presented models.


Author(s):  
A. G. Jackson ◽  
M. Rowe

Diffraction intensities from intermetallic compounds are, in the kinematic approximation, proportional to the scattering amplitude from the element doing the scattering. More detailed calculations have shown that site symmetry and occupation by various atom species also affects the intensity in a diffracted beam. [1] Hence, by measuring the intensities of beams, or their ratios, the occupancy can be estimated. Measurement of the intensity values also allows structure calculations to be made to determine the spatial distribution of the potentials doing the scattering. Thermal effects are also present as a background contribution. Inelastic effects such as loss or absorption/excitation complicate the intensity behavior, and dynamical theory is required to estimate the intensity value.The dynamic range of currents in diffracted beams can be 104or 105:1. Hence, detection of such information requires a means for collecting the intensity over a signal-to-noise range beyond that obtainable with a single film plate, which has a S/N of about 103:1. Although such a collection system is not available currently, a simple system consisting of instrumentation on an existing STEM can be used as a proof of concept which has a S/N of about 255:1, limited by the 8 bit pixel attributes used in the electronics. Use of 24 bit pixel attributes would easily allowthe desired noise range to be attained in the processing instrumentation. The S/N of the scintillator used by the photoelectron sensor is about 106 to 1, well beyond the S/N goal. The trade-off that must be made is the time for acquiring the signal, since the pattern can be obtained in seconds using film plates, compared to 10 to 20 minutes for a pattern to be acquired using the digital scan. Parallel acquisition would, of course, speed up this process immensely.


2002 ◽  
Author(s):  
Sheri Yvonne Nottestad Boyd ◽  
Linda L. Huffer ◽  
Terry D. Bauch ◽  
James L. Furgerson

2020 ◽  
Vol 92 (1) ◽  
pp. 10906
Author(s):  
Jeroen Schoenmaker ◽  
Pâmella Gonçalves Martins ◽  
Guilherme Corsi Miranda da Silva ◽  
Julio Carlos Teixeira

Organic Rankine Cycle (ORC) systems are increasingly gaining relevance in the renewable and sustainable energy scenario. Recently our research group published a manuscript identifying a new type of thermodynamic cycle entitled Buoyancy Organic Rankine Cycle (BORC) [J. Schoenmaker, J.F.Q. Rey, K.R. Pirota, Renew. Energy 36, 999 (2011)]. In this work we present two main contributions. First, we propose a refined thermodynamic model for BORC systems accounting for the specific heat of the working fluid. Considering the refined model, the efficiencies for Pentane and Dichloromethane at temperatures up to 100 °C were estimated to be 17.2%. Second, we show a proof of concept BORC system using a 3 m tall, 0.062 m diameter polycarbonate tube as a column-fluid reservoir. We used water as a column fluid. The thermal stability and uniformity throughout the tube has been carefully simulated and verified experimentally. After the thermal parameters of the water column have been fully characterized, we developed a test body to allow an adequate assessment of the BORC-system's efficiency. We obtained 0.84% efficiency for 43.8 °C working temperature. This corresponds to 35% of the Carnot efficiency calculated for the same temperature difference. Limitations of the model and the apparatus are put into perspective, pointing directions for further developments of BORC systems.


2012 ◽  
Vol 25 (01) ◽  
Author(s):  
A Klein ◽  
G Shafirstein ◽  
E Kohl ◽  
W Bäumler ◽  
M Landthaler ◽  
...  

Author(s):  
FV Güttler ◽  
K Winterwerber ◽  
C Gross ◽  
A Heinrich ◽  
M de Bucourt ◽  
...  
Keyword(s):  

2018 ◽  
Vol 09 (02) ◽  
pp. 65-66
Author(s):  
Alexander Kretzschmar

Zirkulierende Tumorzellen (Circulating Tumor Cells; CTC) sind Prädiktoren von Spät-rezidiven bei Frauen mit einem Hormonrezeptor-positiven (HR-positiv), HER2-negativen frühen Mammakarzinom. Dies ergab eine Proof-of-Concept-Studie, die von Dr. Joseph Sparano, New York, auf dem SABCS 2017 vorgestellt wurde. Spätrezidive machen etwa die Hälfte aller Östrogenrezeptor-positiven Rezidive aus. Genexpressionstests können zwar das Risiko eines Rezidivs insgesamt quantifizieren. Sparanos Arbeitsgruppe glaubt aber, dass CTC bessere Biomarker für Spätrezidive sind.


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