다중혈관 관상동맥 환자에서 y-문합을 이용하여 양쪽 내흉동맥만을 사용한 우회술의 조기 성적

[신간의 별자리x] 우리/미술, 그리고 ‘슬픔의 박물관’

A fast-Fourier-transform method of topography and interferometry is proposed. By computer processing of a noncontour type of fringe pattern, automatic discrimination is achieved between elevation and depression of the object or wave-front form, which has not been possible by the fringe-contour-generation techniques. The method has advantages over moire topography and conventional fringe-contour interferometry in both accuracy and sensitivity. Unlike fringe-scanning techniques, the method is easy to apply because it uses no moving components.

Fourier-transform method of fringe-pattern analysis for computer-based topography and interferometry

We review the recent developments in the area of optical fiber grating sensors, including quasi-distributed strain sensing using Bragg gratings, systems based on chirped gratings, intragrating sensing concepts, long period-based grating sensors, fiber grating laser-based systems, and interferometric sensor systems based on grating reflectors.

Fiber grating sensors

The PASCAL Visual Object Classes Challenge

Cell nucleus as endogenous biological micropump.

Sub-aperture stitching in digital holography (DH) is a very important issue both for the spatial resolution improvement as well as for measuring larger aperture through synthetic enlargement of numerical aperture. In fact, sub-apertures stitching permits to greatly expand the capabilities of optical metrology thus allowing to accurately measure complex optical surfaces such as large spherical and aspheric. Stitching operations can be difficult and cumbersome depending on geometric parameters of specific objects under test. However, here we show that machine learning can definitively aid this process. In fact, here we propose for the first time, to the best of our knowledge, a novel sub-aperture stitching approach based on machine learning applied to an array of different phase-maps sub-apertures recorded by an off-axis digital holographic systems. Essentially, we construct a network according to computation model of sub-aperture stitching and remove the alignment errors and system aberration of sub-aperture maps by training the network. Correct measurement of the surface topography of hemisphere surface is demonstrated thus validating the proposed learning approach. Reported results demonstrate that machine learning can be a useful tool for simplifying the process and for making it a reliable and accurate tool in optical metrology.

Stitching sub-aperture in digital holography based on machine learning.

Liquids are the primary environments in which chemical, physical, and biological processes occur. Considering a liquid bridge as liquid unit volume (LUV) element, it is highly desirable to develop reliable tools for handling such volumes. Herein, a sort of intelligent microfluidic platform based on the pyroelectric‐electrohydrodynamics (EHD) is shown for manipulating liquid bridges and thus performing multiple functions in a flexible and simple way. Several basic operations with liquid bridges using an EHD‐pin matrix based on the pyroelectric effect engineered in ferroelectric crystals are demonstrated. By activating pyro‐EHD effect in predetermined positions (pins of the array), the locomotion and handling of single or multiple LUVs simultaneously are controlled. In particular, multiple operations such as lift, displacement, mixing, stretching, and carrying vector for microparticles, are shown. These tweezers based on a pyro‐EHD matrix can open the route for a multipurpose platform driven by physical intelligence and can be used for driving locomotion and operate manifolds functionalities in many areas of science and technology at microscale as well as nanoscale with advantages to be activated by the sole thermal stimulus, controlled remotely, and in noncontact mode.

Pyroelectric Tweezers for Handling Liquid Unit Volumes

Ferroelectric domain micro structuring of bulk Lithium Niobate is very useful for optoelectronic applications such as non-linear optics employing Quasi-Phase-Matching for efficient harmonic and parametric conversion processes or for the fabrication route for production of novel MEMS devices, like micro-cantilever beams. Quasi-Phase-Matching based applications require periodically reversed ferroelectric structures with periods of the order of micrometers. Precise control of the surface quality and of the domain structure of the micro structured materials is required such as in the case of optical MEMS applications. We here report on the application of Digital Holography as metrological tool for the inspection and characterization of the domain structures in bulk Lithium Niobate samples. This technique allows reconstructing both the intensity and the phase of the microstructures under test and it allows determining quantitatively the phase distribution. Several examples of application of the Digital Holography technique for the numerical reconstruction of the micro-topography of domain structure are presented and discussed.

Pietro Ferraro

Papers

Cell nucleus as endogenous biological micropump.

Stitching sub-aperture in digital holography based on machine learning.

Pyroelectric Tweezers for Handling Liquid Unit Volumes

Characterization of microstructures in lithium niobate crystals by digital holography

Profile measurement of a one-dimensional phase boundary sample using a single shot phase-step method