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Position Analysis of Linkages
Published in Eric Constans, Karl B. Dyer, Introduction to Mechanism Design, 2018
We begin the modeling process by making an outline of the program structure. The objectives of our fourbar linkage analysis program are to: Determine whether the linkage is Grashof.If it is not Grashof, the program should inform the user and then terminate. 3. If it is Grashof, then the program should conduct each of the following steps for every crank angle Calculate the internal angle δ.Calculate θ3 and θ4, the coupler and rocker angles, respectively.Use these angles to calculate the positions of points B, C, and P.Once these calculations are complete, the program should generate a plot that shows the paths of points B, C, and P as the crank makes a complete revolution.
Pictorial Data Preprocessing and Shape Analysis
Published in Sing-Tze Bow, Pattern Recognition and Image Preprocessing, 2002
Another way of obtaining the medial axis transformation of a planar shape is via a Voronoi diagram. First draw the Voronoi diagram of the polygon as shown in Figure 13.24. Denote those vertices of the polygon as convex vertices when the internal angle at the vertex is less than 180°, and as reflex vertices if the internal angle at that vertex is greater than 180°. So in Figure 13.24, vertices within the dashed circles are reflex vertices. Then remove all the Voronoi edges incident with each reflex vertex. We will obtain a medial axis of the polygon as shown in Figure 13.25.
Conjugate Heat Transfer in Forced Air Cooling of Electronic Components
Published in Sung Jin Kim, Sang Woo Lee, for Electronic Equipment, 2020
The coefficient c is a function of the internal angle the boundary makes at point p (local geometry). If the boundary is locally smooth c has the value of 1/2. Otherwise, it may be calculated directly or indirectly [Brebbia et al., 1984]. Now Equation 32 is discretized by dividing the boundary into N number of elements as shown in Figure 26, while assuming that the value of T and q at a point within an element is related to its values at the element nodal points by some interpolation function. If linear interpolation functions are chosen for both temperature and normal flux densities, Equation 32 becomes () ciTi=∑j=1N∫Γj(ψ1q1+ψ2q2)T*dΓ−∑j=1N∫Γj(ψ1T1+ψ2T2)q*dΓ
Effects of backpack weight on the performance of basic short-term/working memory tasks during flat-surface standing
Published in Ergonomics, 2019
Minseok Son, Soomin Hyun, Donghyun Beck, Jaemoon Jung, Woojin Park
For all three experiment tasks, behavioural, physiological and psychophysical response data, which were thought to be helpful in understanding the effects of backpack weight on STM/WM task performance, were collected from the participants during or after each task trial. Postural sway data were obtained using the force plate recordings of the centre of pressure (CoP) position-time profile during the 15 s of the standing task. The sampling frequency of the force plate was 100 Hz. The postural sway data did not include the measurements during the process of putting on and taking off the backpack. Among various postural sway measures, sway area, sway path and sway variance were employed in this study as they had been widely utilised in research studies (Albright and Woodhull-Smith 2009; Diener et al. 1984; Kerr, Condon, and McDonald 1985; Maylor, Allison, and Wing 2001; Panjan and Sarabon 2010; Rode, Tiliket, and Boisson 1997; Shumway-Cook and Woollacott 2000; Thapa et al. 1996). The three postural sway measures are described in Table 2. Sway area was calculated using the area of convex hull which is defined as the smallest polygon in which no internal angle exceeds 180 degrees and contains all sites of occurrence. The vertices of convex hull polygon were computed using the gift wrapping algorithm (Wollseifen 2011). For the sway variance, the medio-lateral (ML) and anterior-posterior (AP) directions were considered.
Emergent chirality in achiral liquid crystals: insights from molecular simulation models of the behaviour of bent-core mesogens
Published in Liquid Crystals, 2018
Juho S. Lintuvuori, Gary Yu, Martin Walker, Mark R. Wilson
Further insights are provided by examining how varies with molecular conformation. For the three-site model (Figure 5(b)) the value of peaks for a dihedral of and varies smoothly as a function of this dihedral. The values of are also shown to depend on the internal angle . For the four-site model, with internal angles of 120, the highest HTP occurs at , and there is an unexpected dip in HTP for (Figure 5(c)). Moreover, changing the internal angle to (Figure 5(d)), as would occur in an oxadiazole-based bent-core mesogen [49], subtly changes the form of the curve, with the maxima shifting to and the local minima shifting to . We note that, for the four-site model, conformations where (which, for an achiral molecule, always have identical torsional energies to conformations with ) have superimposable mirror images and hence .
Generalized formulation for resonance frequency of even polygonal microstrip antennas
Published in Electromagnetics, 2022
Deepankar Shri Gyan, K. P. Ray
As the boundary condition for current loops, the value of surface current (Hθ) becomes zero at the magnetic wall along the circumference. Although, it directly does not produce an accurate result and other corrections are needed for the fringing due to height of the patch and substrate permittivity. The calculation of effective permittivity (or effective area (Helszajn and James 1978)) accounts for these factors of fringing. However, in the proposed approach, the values r takes become a function of number of sides (ns) of the polygon. The equation of the magnetic wall at the vertices of a polygon with internal angle α is given as,