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Definitions and Terminology
Published in Frank Vignola, Joseph Michalsky, Thomas Stoffel, Solar and Infrared Radiation Measurements, 2019
Frank Vignola, Joseph Michalsky, Thomas Stoffel
The dot product of the unit vectors is the cosine of the angle between the two vectors. The angle between the normal to the surface and the Sun’s direction is the solar zenith angle (sza). Therefore, () cos(sza)=sin(lat)⋅sin(dec)+cos(lat)⋅cos(dec)⋅cos(ha)
Vectors and Geometrical Applications
Published in Khalid Khan, Tony Lee Graham, Engineering Mathematics with Applications to Fire Engineering, 2018
A unit vector is any vector that has size (or magnitude) equal to one. In the x, y, z direction of space these unit vectors are defined as follows: i¯,j¯ are unit vectors in the x and y directions in 2-D, respectively, and so vector a¯=3i¯+4j¯ is given by three units along the x-axis and four units along the y-axis and is shown in Figure 3.1. Similarly, i¯,j¯, and k¯ are unit vectors in the x, y, and z directions in 3-D, respectively, and so a vector b¯=2i¯+3j¯+7k¯ is shown in Figure 3.2.
Illumination and Lighting System Design
Published in S. Bobby Rauf, Electrical Engineering for Non-Electrical Engineers, 2021
Lamberts law, also called the cosine law, establishes the relationship between the illuminance on a surface, or target, the illuminance at the source, and the angle “θ” the inclined source radiation (light) portends with respect to the target surface’s normal vector. Where, normal vector would be defined as a unit vector that is perpendicular to the target surface.
An emergent deep developmental model for auditory learning
Published in Journal of Experimental & Theoretical Artificial Intelligence, 2020
Dongshu Wang, Yadong Zhang, Jianbin Xin
where is the bottom-up weight, is the top-down weight, is the input from bottom to top, and is the input from top to bottom, is the unit vector of the normalised synaptic vector , is the unit vector of the normalised input vector . The inner product measures the match degree between these two directions and , because where is the angle between two unit vectors and .