297 results about "X-Coordinate" patented technology

An method for analyzing irreversible apneic coma (IAC) for determining the presence of irreversible apneic coma (IAC) by analyzing the heart rate variability of a brain traumatic patient, thereby providing a physician a reference index to determine whether brain death has occurred. This method includes, at first, recording an electrocardiogram (ECG) from a subject. Then, analyzing R-R interval in said electrocardiogram (ECG), and plotting said R-R interval into Poincaré plot, wherein the X coordinate in said Poincaré plot represents R-R interval(n), and n is a 1˜data number. Y coordinate in said Poincaré plot represents RR(n+1). And, finally, quantifying said Poincaré plot, and obtaining semi-major axis (SD1), semi-minor axis (SD2), and SD1 / SD2 of said Poincaré plot, as well as Poincaré plot area.

A lighting device includes a surface light source (101) and an optical element (103) which is provided with an incident surface (203) and first and second exit surfaces (205, 207). When the center of a light emitting surface (201) is set as P1, an edge point thereof is set as P2, and an axis which passes through P1 and is vertical to the light emitting surface is set as an optical axis, the optical element has such a shape that the optical axis and the vicinity thereof are recessed as compared to the edge. In the cross section of the optical element, when a point on the first exit surface which is disposed at a prospective angle of 15 degrees from the optical axis about P1 is set as P3, a point at which a light beam that exits P2 and travels in parallel to the optical axis intersects the first exit surface is set as P4, and an axis that connects P1 with P2 is set as an X axis, the X coordinate of a point farthest from the optical axis on the first exit surface is equal to or larger than 1.5-times value of P2, and the first exit surface is formed so that an incident angle of light that exits P1 is equal to or larger than a critical angle in 80% or more of an area where the X coordinate is equal to or larger than the value of P3 and an incident angle of light that exits P2 is smaller than the critical angle in 80% or more of an area where the X coordinate is equal to or smaller than the value of P4.

Given a set of elliptic points that satisfy an elliptic polynomial equation defined over a finite field F which requires N-bits to represent its elements, a method of cryptographic encryption and decryption is presented which uses more than one cubic variable that are termed x-coordinates to obtain an elliptic polynomial equation with multi x-coordinates instead of one x-coordinate. The additional nx x-coordinates are used to embed extra message data bits. A nx-fold increase in the number of embedded message data bits in a single elliptic point can be achieved with the improved method. The reason is that the number of points that satisfy an elliptic polynomial equation defined over F and which can be used in the corresponding cryptosystem is increased by a factor of (#F)nx, where # denotes the size of a field. The use of additional x-coordinates can be used to reduce computational complexity. Alternatively, this can be used to increase security by making the bit positions where data bits are embedded known only to the sender and receiver. Also, it can be used as a countermeasure by randomizing the bit positions where data bits are embedded.

Given a set of elliptic curve points defined over a field F(p) and represented in projective coordinate, a method is presented which allows the embedding of data bits in both the X-coordinate and the Z-coordinate of the elliptic curve point when represented in projective coordinate. This makes the number of points that satisfy an elliptic curve equation and which can be used in the corresponding cryptosystem proportional to p2 rather than p. This can be used to either increase security by making the bit positions where data bits are embedded known only to the sender and receiver. Alternatively, it can be used to increase the number of data bits that can be encrypted per single elliptic curve point encryption. In another alternative, it can also be used to reduce p. Also, it can be used as a countermeasure by randomizing the bit positions where data bits are embedded. A similar formulation can be developed for elliptic curves over fields F(2m), as well as special elliptic curves such as Montgomery curves.