Ultrasonic, used in security technology such as car collision avoidance and distance measurement, also can be used in detecting obstruction behind the car when backing up. In this paper, we analyze the interference of ultrasonic signal when transmitting and receiving, and then resolve it by software. There is a blind area and distance limitation in ultrasonic distance measurement .The cause of ...

We discuss 3d interaction techniques for the quantitative analysis of spatial relations in medical visualizations. As an example, we describe the design and implementation of 3d distance measurement tools. The visualization of measurement tools as recognizable 3d objects and a 3d interaction, which is both intuitive and precise, determines the usability of such facilities. Moreover, we explain ...

We experimentally demonstrate that a femtosecond frequency comb laser can be applied as a tool for long-distance measurement in air. Our method is based on the measurement of cross correlation between individual pulses in a Michelson interferometer. From the position of the correlation functions, distances of up to 50 m have been measured. We have compared this measurement to a counting laser i...

Indoor positioning systems (IPSs) suffer from a lack of standard evaluation procedures enabling credible comparisons: this is one the main challenges hindering their widespread market adoption. Traditionally, accuracy based on errors defined as Euclidean distance between true positions and estimated positions. While simple, it ignores obstacles floor transitions. In article, we describe that me...

Abstract Measurement of the pupillary distance (PD) is one important steps spectacles-making process. PD measurement can be done using Ruler, Auto-refractometer, and smartphones’ apps. The study aims to evaluate apps (Pupil Distance Meter Pro from Vistech Project, Pupil for Eye Glasses VR Headset Glassify Me, Ultimate Rule) compared them with Auto-refractometer as gold standard. A total 39 stud...