Immersion Imaging Research Articles

Surface reconstruction accuracy using ultrasonic arrays: Application to non-destructive testing

The accurate non-destructive inspection of engineering structures using ultrasonic immersion imaging requires a precise representation of the surface of the structure. Here we investigate the relationship between surface geometry, surface measurement error using ultrasonic arrays and the total focusing method (TFM) and how this impacts on the ability to image a feature within a component. Surfaces shaped as sinusoids covering combinations of surface wavelengths (0.8 to 32λwater) and amplitudes (0.6 to 9λwater) are studied. The surface reconstruction errors are shown to cause errors in imaging, such as reduced amplitude and blurring of the image of a side-drilled hole. These reconstruction errors are shown to increase rapidly with the maximum gradient of the sinusoid. Sinusoidal surfaces with maximum gradients <45° lead to average surface reconstruction errors <λwater and amplitude imaging errors within 6 dB of the flat-surface case. It is also shown that very poor results are obtained if the surface gradient is excessively steep.

Virtual reality in advanced medical immersive imaging: a workflow for introducing virtual reality as a supporting tool in medical imaging

Radiologic evaluation of images from computed tomography (CT) or magnetic resonance imaging for diagnostic purposes is based on the analysis of single slices, occasionally supplementing this information with 3D reconstructions as well as surface or volume rendered images. However, due to the complexity of anatomical or pathological structures in biomedical imaging, innovative visualization techniques are required to display morphological characteristics three dimensionally. Virtual reality is a modern tool of representing visual data, The observer has the impression of being “inside” a virtual surrounding, which is referred to as immersive imaging. Such techniques are currently being used in technical applications, e.g. in the automobile industry. Our aim is to introduce a workflow realized within one simple program which processes common image stacks from CT, produces 3D volume and surface reconstruction and rendering, and finally includes the data into a virtual reality device equipped with a motion head tracking cave automatic virtual environment system. Such techniques have the potential to augment the possibilities in non-invasive medical imaging, e.g. for surgical planning or educational purposes to add another dimension for advanced understanding of complex anatomical and pathological structures. To this end, the reconstructions are based on advanced mathematical techniques and the corresponding grids which we can export are intended to form the basis for simulations of mathematical models of the pathogenesis of different diseases.

Daring the Meaning, or Cyberspace that Matters. Criticism-Creativity and Online Education

This paper focuses on online education and generic competences such as criticism and creativity. It brings to the fore theories that address processes of meaning making (i.e., a psychological constructionist account of the brain basis of emotion-the conceptual act model (Lindquist et al., 2012; Barrett et al., 2014) and reflect on various patterns of meaning making comprising those that lead to criticism and creativity (i.e., the Deleuzian and Guattarian (1987; 2009) philosophical accounts of affect, concept and stratum) to inspire pedagogical practices that aim to create critically-creative abilities among students. Concomitantly, it seeks to reflect on how such pedagogical undertakings can be actualized in online education and on the possibilities online environment offers to promote criticism and creativity among graduates. By posing questions related to teaching methods, learning activities, software and hardware, and their combinations in online education, and by addressing and problematizing concepts and phenomena of immersion and DFI-digital facial image, I will make an effort to not only highlight, what I call, the promises of cyberspace, but also ponder on how the aforementioned pedagogical practices can be actualized online.

올림픽경기 중계방송의 미디어 수요 행태 변화 경향 : 2008 베이징, 2012 런던, 2016 리우 올림픽을 중심으로

This study aims to extend the centric recognized about the existing ground radio wave TV and intends to assert the need for the role of media by analyzing the usage patterns of the changes made to the media audience of sporting events of the recent Olympic Games.BR The primary conclusions showed a tendency generally, watching the Olympic games using the internet, mobile phones, and social media, regardless of the time and place, the trend had emerged that especially using new media will continue to share further increased.BR The Olympic Games content acceptance is mainly made up of one-person media. The use of the Olympic relay broadcasts is based on the use of fused media that the merits of each media. Consumption of Olympic Games contents consumed lately is increasing selectively according to personality and taste in the sports broadcasting contents market. Finally, demand for content that is realistic and immersive VR imaging systems will increase for Olympic games.

Microstructure, phase composition and mechanical properties of plasma sprayed Al2O3, Cr2O3 and Cr2O3-Al2O3 composite coatings

In the present work, chromia and alumina coatings were produced by atmospheric plasma spray process. Phase composition, microstructure and mechanical properties of chromia and alumina composite coatings on carbon steel substrates were studied and compared to individual Cr2O3 and Al2O3 coatings. Morphology and microstructure of coatings were characterized using scanning electron microscopy equipped by EDS. The porosity of the plasma-sprayed coatings was measured by the Archimedes water immersion technique and image analysis method. X-ray diffraction was employed to identify phase composition of coatings. Also some mechanical properties such as bonding strength, Vickers microhardness and resistance to crack propagation of coatings were measured. The results showed different phases for Al2O3 in different coatings while Cr2O3 remained in eskolaite phase in all of the coatings. Addition of 75wt% Cr2O3 prevented formation of metastable and undesirable γ-Al2O3 phase. Alumina and rich-alumina coatings showed denser microstructure and higher flattening degree of splats as well as lower surface roughness. Bonding strength of individual Cr2O3 and Al2O3 coatings was higher than composite one. Vickers microhardness increased with addition of Cr2O3. Alumina improved spray ability and crack propagation resistant of chromia.

GPUを用いた全周囲立体CG映像の実時間生成(「テレイマージョン」特集)

GPUを用いた全周囲立体CG映像の実時間生成(「テレイマージョン」特集)

Image-guidance technology and the surgical resection of spinal column tumors.

Precision imaging is paramount to achieving success in surgical resection of many spinal tumors, whether the goal involves guiding a surgical cure for primary tumors or improving neurological decompression for metastatic lesions. Pre-operatively, image visualization is intimately involved with defining a clear target and surgical planning. Intra-operatively, image-guidance technology allows for surgeons to maximize the probability for gross total resection of spinal cord tumors and minimize damage to adjacent structures. Through this review, it is evident that spinal surgery has undergone significant advancements with the continued technological progression of different modalities of imaging guided technologies. Sophisticated imaging techniques compliment the surgeon's knowledge by providing an intraoperative reference to spinal column anatomy. This review discusses research efforts focusing on immersive imaging guided interactions with subject specific medical images that could enhance a surgeon's ability to plan and perform complex spinal oncology procedures with safety and efficiency.

Immersive Interactive SAR Image Representation Using Non-negative Matrix Factorization

Earth observation (EO) images clustering is a challenging problem in data mining, where each image is represented by a high-dimensional feature vector. However, the feature vectors might not be appropriate to express the semantic content of images, which eventually lead to poor results in clustering and classification. To tackle this problem, we propose an interactive approach to generate compact and informative features from images content. To this end, we utilize a 3-D interactive application to support user-images interactions. These interactions are used in the context of two novel nonnegative matrix factorization (NMF) algorithms to generate new features. We assess the quality of new features by applying k-means clustering on the generated features and compare the obtained clustering results with those achieved by original features. We perform experiments on a synthetic aperture radar (SAR) image dataset represented by different state-of-the-art features and demonstrate the effectiveness of the proposed method. Moreover, we propose a divide-and-conquer approach to cluster a massive amount of images using a small subset of interactions.

Quantification model of proper curvature for large‐sized curved TVs

AbstractWe present a feasible modeling method to estimate the proper curvature for large‐sized curved TVs. We especially focused on two factors – preference and perceived distortion – to be considered to determine the proper curvature. The preference includes a number of advantages that people expect to fulfill the possibilities of a more immersive image and sense of realism from curved display. On the other hand, the perceived distortion means the side effects that people can notice uncomfortable feeling caused by the shape of a curved one. In order to find out how two factors would be different as a number of conditions like curvature, size, and viewing angle change, a series of subjective assessments were conducted. The evaluation results show that both the preference and perceived distortion vary with the conditions considerably. We performed the statistical analysis based on the results and proposed the quantification model of proper curvature, which has higher preference and less perceived distortion, for various‐sized curved TVs.

Implementation of an augmented reality interface to reproduce and compare soundscapes

Soundscape design is a growing concern in architectural practice; yet, conveying soundscape properties is a challenge. Quantitative measures like decibel levels offer little utility; birdsong and squealing brakes may be at the same frequency and level, yet one is obviously preferable. Furthermore, visual qualities of the scene have a substantial effect on perception of the acoustic environment. To improve communication between acoustic designers, architects, and clients, an augmented reality interface has been designed to allow comparisons of soundscapes and their relationships to the built environment. The interface consists of a physical scale model, printed data, and a tablet application. The augmented reality application uses a machine vision algorithm to recognize the model and allow on-screen interaction. On the tablet, measurement points are displayed on a live image of the model at their respective locations, and the user may select a point by touch, which will begin sound playback and display an immersive image of the scene. The participant can then look around a spherical image of the scene using the tablet as a movable window, and thereby listen to the environment with appropriate accompanying visual cues. The interface has been a useful tool to communicate urban sound issues.

Colonoscopy for Colorectal Cancer Screening: Current Challenges and Future Directions

It is estimated that over 50,000 people will die from colorectal cancer (CRC) in 2014, making CRC the third leading cause of cancer death in the USA. During the last decade, we gained a better understanding of CRC pathophysiology and improved techniques for CRC prevention. Colonoscopy, as a cancer prevention measure, is essential in this task. Our article will review several aspects of colonoscopy and its use in CRC prevention. In addition, we will cover non-technical aspect such as quality measures, improving colonoscopy uptake, new bowel preparation formulations, sedation, and quality metrics. Next, we will discuss advances in technology and techniques including water immersion, new colonoscopes, and new imaging methods. Finally, we will cover two areas of major recent interest, “resect and discard” and sessile serrated polyps.

Efficient immersion imaging of components with nonplanar surfaces.

Ultrasonic array inspection of a component with a nonplanar surface can be achieved in immersion using a liquid layer to couple ultrasonic waves from an array probe into a solid structure. This paper presents an efficient way to compute the appropriate element time delays in immersion without compromising the measurement accuracy. In the proposed imaging process, the surface geometry is first measured ultrasonically by forming an image of the component surface in the couplant. This leads to a set of discrete points that define the surface profile of the component. The propagation time from an array element to a point in the component is then determined by a grid search of candidate ray-paths through each surface point to identify the one that yields the shortest traveling time. Propagation times in the component are first generated on a coarse mesh of points and then these values are linearly interpolated to find the propagation time to each image pixel. The computed propagation times are finally used to reconstruct an image of the component interior. An analytical model is developed to determine a relationship between estimated propagation time errors and their effect on the array inspection in terms of signal amplitude from a reflector. For nominally normal incidence inspection of a metallic component with a minimum surface radius of 30 wavelengths immersed in water, it is found that the surface of the component can be adequately described by points spaced by one wavelength and that delays can be computed on a coarse grid of points spaced at 3 wavelengths. With these parameters, the reduction in amplitude of a point target in the component is shown to be less than 1 dB.

Human Pose Estimation and Tracking via Parsing a Tree Structure Based Human Model

Human pose estimation and tracking is the task of determining the states (location, orientation, and scale) of each body part over time. It is important for many vision understanding applications, such as visual interactive gaming, immersive virtual reality, visual surveillance, and content-based image retrieval. However, it remains a challenging task due to unknown image background, presence of clutter and especially the high dimensional state space (usually 30+ dimensions). In this paper, we contribute to human pose estimation and tracking in two aspects. First, we design two efficient Markov Chain dynamics under the data-driven Markov Chain Monte Carlo framework to effectively explore the high dimensional state space. Second, we parse the tree structure state space into a lexicographic order according to the image observations and body topology, and the optimization process is conducted in this order. This realizes a much more efficient exploration of the state space than the sampling based search or exhaustive search, and thus achieves a tremendous speed-up. Experimental results demonstrate the efficiency and effectiveness of the proposed method in estimating and tracking various kinds of human poses, even against cluttered backgrounds, in poor illumination or under partial self-occlusion.

Petrographic characterization of coals as a tool to detect spontaneous combustion potential

Textural features of 25 worldwide coals were studied after slow oxidation processing (0.5°Cmin−1 from 20 to 250°C in air) using oil immersion microscopy and image analysis techniques. The characterization of samples, before and after oxidation, showed important changes in vitrinite reflectance with high reactive coals, which also related to their intrinsic self-oxidation potential. The morphology of the coal particles was also altered after the oxidation, to produce at least six different morphotypes. Particles with ‘homogeneous change of reflectance’ and particles with ‘oxidation rims’ were predominant in the samples studied, which related to boundary reactive conditions (kinetic and diffusion control of the reaction respectively). These textural characteristics indicate how particles interacted with oxygen at low temperatures, which could be used to predict the most probable pathway during the early stages of oxidation which could then lead to a spontaneous combustion event. The magnitude of the reflectance change and the morphological characteristics of samples studied were also related to the reactivity properties, providing an additional source of information to identify coals prone to spontaneous combustion.

A new implementation of image-processing engine for 3D visualization and stereo video stream display

This paper presents a new implementation of a high-definition image-processing engine, which mainly targets the 3-dimensional (3D) visualization and stereo video stream display of binocular display equipment. The engine is compatible with the mainstream analog and digital stereo videos in component format and is able to receive stereo composite video broadcast signals using an integrated analog stereo video decoder. The four modules include a spatiotemporal scaling transform engine, a 2D–3D converter, an image animating engine, and a 2D scalar operating in pipeline architecture to implement the video format conversion and the stereo effect enhancement. Furthermore, the data access, hardware structure, and system-level configurations are optimized. Finally, the proposed architecture is realized by 0.18 μm CMOS technology. The application-specific integrated circuit verification results show that the engine can generate a strong feeling of 3D immersion and high-definition image quality with minimal flicker. The chip has wide compatibility and an uppermost 1080P-processing capacity, which has approximately 3.5 million gates with about 43 mm2 die size.

Transfer, Imaging, and Analysis Plate for Facile Handling of 384 Hanging Drop 3D Tissue Spheroids

Three-dimensional culture systems bridge the experimental gap between in vivo and in vitro physiology. However, nonstandardized formation and limited downstream adaptability of 3D cultures have hindered mainstream adoption of these systems for biological applications, especially for low- and moderate-throughput assays commonly used in biomedical research. Here we build on our recent development of a 384-well hanging drop plate for spheroid culture to design a complementary spheroid transfer and imaging (TRIM) plate. The low-aspect ratio wells of the TRIM plate facilitated high-fidelity, user-independent, contact-based collection of hanging drop spheroids. Using the TRIM plate, we demonstrated several downstream analyses, including bulk tissue collection for flow cytometry, high-resolution low working-distance immersion imaging, and timely reagent delivery for enzymatic studies. Low working-distance multiphoton imaging revealed a cell type-dependent, macroscopic spheroid structure. Unlike ovarian cancer spheroids, which formed loose, disk-shaped spheroids, human mammary fibroblasts formed tight, spherical, and nutrient-limited spheroids. Beyond the applications we describe here, we expect the hanging drop spheroid plate and complementary TRIM plate to facilitate analyses of spheroids across the spectrum of throughput, particularly for bulk collection of spheroids and high-content imaging.

Limit of Line End Shortening Correction under Single Exposure in 193 nm Immersion Lithography

As the lithography starts to approach the limit of 193 nm immersion imaging capability under single exposure, successful development of a lithographic process rely on the good balance of the process parameters, such as the exposure latitude and depth of focus for the dense, semi-dense, isolated structures, MEF, LWR, proximity bias, etc. Such balance requires very good understanding of the inter-relationship among them and ways to give reasonable specification to the important materials such as photoresist and photomasks. Although, relatively speaking, 1-dimensional structures, such as, line and space or even square contacts are relatively easy to understand and model with accurate simulations, which is close to perfect, 2-dimensional structures are not easy to understand physically and the simulation for them are up to larger errors. Since previous study on this subject was either done at larger ground-rules or lack of good physical understanding in the simulation, this paper will use both experimental wafer measurement data and physical modeling to probe the limits for the OPC correction of line (or space) end shortening structures at around 50 nm dimensions. Several structures will be studied in theory and wafer data.

Quick-Time VRTM: when medical education meets virtual reality

Learning medicine is a difficult process to undertake, partially due to the complexity of the subject and limitations of traditional methods of teaching (lectures, textbooks, laboratory and anatomical dissections). These resources have been effective for decades, even though presenting intrinsic drawbacks. Textbooks are non-interactive education tools and do not provide any three dimensional experience. Cadaver dissection is an invaluable aid to learn anatomy. It provides an immersive, interactive experience allied with an inimitable tactile feedback. However, it has several limitations, including availability of specimens, costs and a substantial time commitment. Computer based virtual reality methods may overcome these drawbacks and provide interesting alternatives for medical training. Technological advances have generated great expectations for the use of computer-based virtual reality technologies in medical education, mainly anatomy and surgery. However, these Virtual Reality tools for general medical education are expensive due to the equipment necessary to create highly detailed, immersive three-dimensional image environments with real time friendly user interactivity. The concepts of Virtual Reality methods that generate immersive environments, as well as those that create simulated objects with interactive viewing features may be contemplated by the QuickTimeTM which is one of the technologies that can be successfully used for interactive, photorealistic displaying of medical images (radiological, anatomical and histological) and interaction on current generation of personal computers at a low and accessible cost. In this paper, the authors provide an overview of the Quick Time Virtual Reality methods aiming to introduce them to medical educators and illustrate their application on medical training.

There's no I in YouTube: social media, networked identity and art education

Social media represent a paradigmatic shift in the use of digital technologies, and provide new possibilities for art educational application, implementation and interrogation. These technologies also challenge notions of authenticity, authorship and authority that have been central to the modernist core of the field. Individuals who are using social media as a medium challenge the authenticity of the art object, the authorship of the artist and the authority of the museum/gallery system. This article first provides an overview of three forms of interaction of social media: tagging, the mash-up and simulated environments. These forms then provide a context for discussion of the potential uses for social media within the field of art education, as well as pointing to the limitations of such technologies. Then there is a consideration of the pedagogical possibilities and problems inherent to three specific aspects of social media: Flickr and the hyperlinked image; YouTube and the moving image; and Second Life and the immersive image. This examination of social media may help other art educators to understand the importance of networked digital technologies in the lives of individuals and groups worldwide. More importantly, they may see pedagogical implications in the visualities such technologies produce, the identities formed in virtual environments and the epistemologies that develop from networked social media.

Immersion Lithography: Photomask and Wafer-Level Materials

Optical immersion lithography utilizes liquids with refractive indices &gt;1 (the index of air) below the last lens element to enhance numerical aperture and resolution, enabling sub-40-nm feature patterning. This shift from conventional dry optical lithography introduces numerous challenges requiring innovations in materials at all imaging stack levels. In this article, we highlight the recent materials advances in photomasks, immersion fluids, topcoats, and photoresists. Some of the challenges encountered include the fluids' and photomask materials' UV durability, the high-index liquids' compatibility with topcoats and photoresists, and overall immersion imaging and defectivity performance. In addition, we include a section on novel materials and methods for double-patterning lithography—a technique that may further extend immersion technology by effectively doubling a less dense pattern's line density.