Displacement (vector)

About: Displacement (vector) is a research topic. Over the lifetime, 24669 publications have been published within this topic receiving 264944 citations.

Remote measurement of displacement by use of a γ-ray source

Abstract: A technique is described by which displacements can be measured remotely. The screening of a γ-ray source is altered by the displacement, so altering the intensity of radiation, which can be measured some distance away even outside a thick, absorbent wall. The method is appropriate for displacements down to a fraction of a millimetre.

Reliability assessment of the rotation algorithm for earthquake damage estimation

Abstract: A rotation algorithm was developed that computes the slope of permanently deformed columns subjected to earthquake ground motion using micro-electro-mechanical system accelerometers. Previous studies by the authors have shown that the algorithm can provide estimates of the residual displacement in the column, and thus the story drift can be evaluated. The algorithm was validated through applications to columns that deflect in single and double curvature. Information from tests on such columns conducted at various laboratories was used to conduct the study. The optimal number of sensors and their placement on the test columns were determined through a series of numerical analyses. The accuracy of the rotation and displacement estimates is assessed under the assumptions of zero-noise sensors and perfect measurements. In this paper, the effect of measurement error and sensor noise on the predicted rotations and corresponding deformations is studied in order to provide bounds on the accuracy of the rotation a...

Automatic focusing device for scanning electron microscope

Abstract: PURPOSE: To improve efficiency and further to improve reliability of data by correcting a focusing position by a correction value registered in a focal point correction register device. CONSTITUTION: A stage 15 is driven to move a sample 4 in accordance with data of a wafer register device, and a correction value corresponding to a coordinate of the stage 5 is selected in accordance with a kind of a wafer and treating process by a focal point correction register device 12. When an automatic focusing mechanism is started to detect a focusing position, the focal point correction register device 12, based on a registered correction value δ0, calculates displacement relating to the focusing position, to correct an exciting current of an objective lens 3, and a focal point is set to a desired focal position, to perform focusing. Then in the case of providing displacement between a focal position decided to be a focusing position by an automatic focusing function and a focal position in a part actually desired to be observed, automatic focusing can be performed to a position desired to be observed. COPYRIGHT: (C)1995,JPO

Point light source welding seam scanning detection method

Abstract: The invention discloses point light source welding seam scanning detection method, which comprises the steps of emitting point laser to a preset point on a welding seam of a weldment; acquiring reflected light of the point laser; acquiring the relative distance between the preset point and a laser displacement sensor after measurement processing; moving the weldment towards a first direction in sequence by a first preset distance, and acquiring the relative distance between each detection point in the first direction and the laser displacement sensor; moving the weldment towards a second direction in sequence by a second preset distance after each detection point in the first direction is detected, moving the weldment towards the first direction in sequence by a third preset distance, and acquiring the relative distance between each detection point in the third direction and the laser displacement sensor; and calculating shape parameters of the welding seam according to the relative distance between each detection point in the first direction and the laser displacement sensor and the relative distance between each detection point in the second direction and the laser displacement sensor, and generating corresponding characteristic signals by using the shape parameters. The point light source welding seam scanning detection method effectively realizes automatic detection for forming conditions of a welding seam.

Arbitrary convex polygon block discrete unit method based on distance potential function

Abstract: The present invention discloses an arbitrary convex polygon block discrete unit method based on a distance potential function. The method mainly comprises the following steps of establishing an ore-boundary discrete model; performing contact detection on all block units by using an NBS contact detection method, and obtaining each block unit and the block units in contact with each block unit; performing contact force calculation on the block units in contact with each other through a block discrete unit distance potential function, and obtaining contact force and moment acting on the block units; and furthermore calculating speed and displacement of the block units by a velocity verlet algorithm, and finally gradually updating displacement of the ore block units, namely the specific motion morphology thereof. The definition of the distance potential function is adopted, physical significance of the potential function is defined, the motion morphology of arbitrary convex polygon blocks is calculated by a block discrete unit method based on the distance potential function, the method can be used for motion morphology research of rocks and ores, and actual guidance is provided for actual mining site projects.