P‐5.11: The Influence of Optical Defocus on Autostereoscopic Image

This paper proposes a method to reduce stereoscopic crosstalk in time-division multiplexing parallax barrier system with reduced power consumption, where a fine slit pattern is generated by projecting LED striped light bars through a lenticular lens. When LEDs and a lenticular lens are used to generate a slit pattern, crosstalk level becomes higher than that of the system using a pair of LCD panels because the LED backlight does not fully synchronize with the update of image in the LCD panel. To overcome this problem, the lighting time of LED light bars is shortened, which enables reduction of crosstalk without lowering the ratio of luminance to power consumption.

To create 3D lenticular comics, a lenticular lens and printing output are combined, making various visual effects such as animation and auto-stereoscopic displays possible. 3D lenticular content is created easily by placing a lenticular lens on an image composed especially for viewing in 3D. With lenticular technology, 3D images are created through a lenticular lens that combines two images, one to be viewed by the left eye and the other by the right eye. The type of lenticular lens to be used is selected depending on the purpose, effect, and viewing distance. Although many 3D lenticular comics currently published consist of a single character or a scene, it is expected that normal comics, which include both pictures and text and which have many pages and relatively long stories, will start to be published as 3D lenticular comics. In this case, the readability of the text is essential. Getting a high readability on text containing Chinese characters is especially difficult because the characters are made of complex combinations of thin lines. However, there has been little research reported in this field. Therefore, we conducted experiments and investigated the relationship between readability and the resolution of the lenticular lenses used to create the stereoscopic effect. From the results of these experiments, we propose a guideline for determining the resolution of 3D lenticular comics.

When creating a multi-view image for multi-view 3D display with one camera, the camera has to be moved from one viewpoint to another viewpoint. However, this method takes long time and can not get images of a moving object. In this paper, we proposed the method for capturing a multi-view image by one step. In order to capture a multi-view image, the lenticular lens is used in our proposed system. The captured multi-view image becomes reverse by using the lenticular lens. Before calculating the best observation distance, a reversal processing is performed. To display a multi-view 3D image by the multi-view image, the same lenticular lens is used. As an experiment result, we got the multi-view image by our proposal system. When we laid the multi-view image under the lenticular lens, a multi-view 3D image with deep feeling was confirmed.

Thermal-flow-elastic coupling (TFEC) numerical simulation platform has been an essential platform for designing turbo engines with high performance and efficiency. Generally, TFEC numerical simulation was achieved by predicting thermal and stress fields with finite element methods, while flow fields with finite difference methods, but such calculation was not popular in engineering design, because of too much size of data exchange and lower computing efficiency. However these shortcomings will not exist by using finite difference methods for all of the fields. To establish a three dimensional multifunction numerical simulation platform for turbines for all of the fields, the key technique was studied firstly. The technique included analysis on physical models, establishing of mathematical model equation, usage of curvilinear coordinate platform, construction of high accuracy difference scheme and selection of boundary conditions for multi-field coupling simulation. Then the algorithm including domain decomposition one and parallel one were studied to accelerate the coupling simulation. The purpose was to develop a completed TFEC numerical simulation platform by using of finite difference method and to apply the platform for numerical simulation in turbines. Firstly codes for predicting flow field in passage, thermal and stress fields in solid body were developed. Then a simple TFEC numerical simulation platform for turbines was obtained. The single code for predicting flow field was verified with experimental data, and the other two codes were validated with thermal and elastic analytic solutions respectively. And satisfying results were obtained. Then the code for thermal-flow was validated with experimental data of Mark II blade, and the code for thermal-elastic coupling simulations was validated with a cylinder by an analytic solutions. All of these are good basics for completing TFEC numerical simulation platform using finite difference methods for all of the fields and computing TFEC numerical simulation in a turbo engine.

Numerical simulation platform for slab track systems subjected to a moving vehicle

In the present study, we propose a novel projection mapping using a 3D light-field image as a light source. In recent years, spatial augmented reality has evolved into dynamic projection mapping that extends the target to moving objects. However, spatial augmented reality causes multiplexing of projection and measurement equipment, which causes various problems, such as increased psychological pressure on users and a reduced production effect. Therefore, based on the concept of stealth projection, which hides the projection device using aerial imaging technology, we propose a dynamic projection mapping method using a 3D light-field image generated in real time according to the position and orientation of the target object. As a result, a simple light-field projector consisting of an LCD panel and a lenticular lens provides projection mapping for moving objects while visually hiding the projection devices.

Using lenticular lenses to realize auto-stereoscopic displays has become increasingly popular in the TV industry, especially in the area of developing multi-view glasses-free 3D TV. Each lenticular lens has many sublenses through which the light is diverted in different directions. A multi-view TV display projects a vertically rotated 3D image to a viewer that seamlessly matches his or her sideways movement. To do so, it poses a very stringent requirement on machining lenticular lens mold. Using a tailor-made cutting tool, the profile of the lenticular grooves can be machined very precisely, and in a very efficient manner; however, the groove width might vary due to elastic bouncing. Such variation of the groove width leads to disparity in the light intensity entering the left and right eye of the viewer. The 3D perception would then unavoidably deteriorate. Thus, a corrective machining method must be developed to fine-tune the groove width. In this paper, a method involving transverse cutting perpendicular to the axes of the lenticular grooves is proposed, in which the cutting is done transversely across the grooves using a single point diamond tool. The depth of corrective cut is 1 μm, and the errors in the groove widths can be corrected to ±200 nm.

A high‐resolution autostereoscopic three‐dimensional (3D) display is proposed. It comprises two light source arrays (LSAs), a transparent liquid crystal display (LCD) panel, a scattering layer, and a lenticular lens. Light emitted from the LSAs is directed onto the transparent LCD panel, which projects the opening units corresponding to different parallax image pixels into distinct spatial locations, thereby creating new pixels. These new pixels are modulated and reconstructed by the scattering layer, incorporating both the original parallax image pixel information and the information from adjacent pixels post‐differentiation. Consequently, when the new pixels are projected through the lenticular lens to the viewpoint, a high‐resolution 3D image is displayed. The experimental results demonstrate the validity of our proposed autostereoscopic 3D display.

It is of great significance to study the deep integration of manufacturing technology and new-generation information communication technology under vibration interference of machine tools to improve the intelligence level of CNC machine tools. In this paper, a numerical control manufacturing workshop affected by vibration in discrete manufacturing is taken as the research background, and a solution for a digital workshop operation simulation platform based on the industrial internet is proposed. By constructing the simulation environment of the operation process of the digital factory, the generation and transmission of manufacturing information in the digital factory are simulated. The application architecture of the machining workshop based on a numerical control simulation platform is proposed, and the business process of the numerical control machining workshop is analyzed. Then, the key technologies of NC machine tool modeling, synchronous mapping of data and model, data integration, and fusion are studied. Through the integration and implementation of the NC machine tool simulation platform in the machining workshop, the top-down data instructions can be issued accurately, and the bottom-up feedback information can be confirmed in time. Finally, the system is applied to the electronic information and ship machining workshop to verify the effectiveness of the system framework and method proposed in this paper.

We propose novel depth-fused three-dimensional (DFD) method using polarization distribution, which is one kind of multifocal plane display that provides autostereoscopic image with small visual fatigue. The DFD method is based on the characteristic of human depth perception when the luminance-modulated two-dimensional (2D) images are overlapped. The perceived depth position is decided by the luminance ratio of each plane. The proposed system includes the polarization selective scattering films and the polarization modulating device. The polarization selective scattering film has the characteristics of partial scattering according to the polarization state and transmits the rest light from the scattering. When the films are stacked with the scattering axis rotated, each layer of film provides different scattering ratio according to the incident polarization. Consequently, the appropriate modulation of polarization can provide DFD image through the system. The depth map provides depth information of each pixel as a gray scale image. Thus, when a depth map is displayed on a polarization modulating device, it is converted into a polarization distributed depth map. The conventional twisted nematic liquid crystal display can be used as a polarization modulating device without complicated modification. We demonstrate the proposed system with simple experiment, and compare the characteristic of the system with simulated result.

<p indent="0mm">In this paper, magnetic confinement fusion is introduced focusing on its fluid mechanics relevant to a liquid lithium divertor. The main research problem is the flow stability of a liquid metal film flow under the influence of a magnetic field. Therefore, a linear stability analysis numerical calculation platform and a direct numerical simulation platform are developed to understand the effect of magnetohydrodynamics on the flow stability of thin films. These platforms will be used to reveal the physical mechanism of a magnetic field on the film flow stability and to guide the design and implementation of a liquid lithium divertor.

Three-dimensional (3D) light-field displays (LFDs) suffer from a narrow viewing angle, limited depth range, and low spatial information capacity, which limit their diversified application. Because the number of pixels used to construct 3D spatial information is limited, increasing the viewing angle reduces the viewpoint density, which degrades the 3D performance. A solution based on a holographic functional screen (HFS) and a ladder-compound lenticular lens unit (LC-LLU) is proposed to increase the viewing angle while optimizing the viewpoint utilization. The LC-LLU and HFS are used to create 160 non-uniformly distributed viewpoints with low crosstalk, which increases the viewpoint density in the middle viewing zone and provides clear monocular depth cues. The corresponding coding method is presented as well. The optimized compound lenticular lens array can balance between suppressing aberration and improving displayed quality. The simulations and experiments show that the proposed 3D LFD can present natural 3D images with the right perception and occlusion relationship within a 65° viewing angle.

A numerical analysis technique is demonstrated for the measurement of the shielding effectiveness (SE) of a conducting box cavity with apertures based on the use of a vibrating intrinsic reverberation chamber (VIRC) with the nested chamber approach. VIRC generates a multipath electromagnetic environment and can measure the SE for various polarizations and angles of incidence compared with the conventional plane-wave excitation method. The finite-difference time-domain method is applied to model a configuration for shielding effectiveness measurements and simulation of the configuration behavior. We investigated its usability based on the application of computational electromagnetics validation methods, such as the feature selective validation method, with reference results obtained with the conventional plane-wave excitation approach. The proposed VIRC numerical analysis platform used for the prediction of the SE of conducting cavities with apertures yields good outcomes even when the cavity exhibits a dominant resonance.

The dynamics of the 1.5-degree-of-freedom model of towed wheel is investigated. Dry friction at the king pin is considered, leading to a non-smooth dynamical system. Beyond analytical and numerical linear stability analysis, the nonlinear vibrations are investigated by numerical bifurcation analysis with smoothing and by numerical simulations with event handling. The effect of dry friction at the king pin on the birth of separated periodic branches is presented on bifurcation diagrams. The presence of bistable parameter domains is also shown. The effect of smoothing is investigated by comparing bifurcation diagrams of the smoothed and the original non-smooth systems.

A newly emerged technique known as Digital Rock Physics demonstrates an ability to characterize properties of the porous media. This technique is based on the imaging of rock micro-structure using a micro-CT scanner. Images are segmented based on their grayscale values to extract pore network from the solid phase. Then, rock properties are estimated using extracted pore network and numerical simulations. Porosity and absolute permeability are two essential properties that can be derived from grayscale images. These properties represent storage and flow capacity of the rock. Some rock samples, particularly carbonate rocks have complex micro-structures at several length scales. Due to limited image resolution, 3D images of carbonate rock may not have top-bottom pore connectivity. In this case, one unable to simulate fluid flow throughout the images. Therefore, permeability is computed on small image sub-volumes, where pore connectivity is revealed locally. Such approach requires long simulation runs. In this paper, a new approach is proposed to estimate permeability from 3D carbonate rock images, where pore connectivity is not revealed from top to bottom. In this approach, first a number of texture classes that represents various textures in the 3D image are identified. For each identified texture class, several sub-volumes from the 3D image are extracted. These sub-volumes are representative of the identified textures and have local pore connectivity. To simulate fluid flow through the pore network of extracted sub-volumes Lattice Boltzmann method (LBM) is used. Permeability is then calculated using Darcy's equation. After determining permeability ranges of each textural class, the 3D image is divided into sub-volumes. Then, each sub-volume is classified into one of the specified texture classes using a modified version of the texture classification algorithm, Local Binary Pattern (LBP). In this study, traditional 2D LBP texture feature vector is adopted to handle 3D volume classification. After classification, each sub-volume is assigned a permeability value that is equivalent to its texture class. Finally, the permeability of the whole 3D image is computed by simulating Darcy's flow through the all sub-volumes. Preliminary outcomes of the proposed technique indicate that it is able to closely estimate experimental results from the laboratory.