Tiling technology for large‐area direct‐view displays

Abstract— In this paper, the optical and system characteristics of large‐area displays based upon ITrans tiling technology is described. The characteristics of these displays are compared to those of other large area display technologies.     

Low bandwidth desktop and video streaming for collaborative tiled display environments

High-resolution display environments built on networked, multi-tile displays have emerged as an enabling tool for collaborative, distributed visualization work. They provide a means to present, compare, and correlate data in a broad range of formats and coming from a multitude of different sources. Visualization of these distributed data resources may be achieved from a variety of clustered processing and display resources for local rendering and may be streamed on demand and in real-time from remotely rendered content. The latter is particularly important when multiple users want to concurrently share content from their personal devices to further augment the shared workspace. This paper presents a high-quality video streaming technique allowing remotely generated content to be acquired and streamed to multi-tile display environments from a range of sources and over a heterogeneous wide area network.The presented technique uses video compression to reduce the entropy and therefore required bandwidth of the video stream. Compressed video delivery poses a series of challenges for display on tiled video walls which are addressed in this paper. These include delivery to the display wall from a variety of devices and localities with synchronized playback, seamless mobility as users move and resize the video streams across the tiled display wall, and low latency video encoding, decoding, and display necessary for interactive applications. The presented technique is able to deliver 1080p resolution, multimedia rich content with bandwidth requirements below 10 Mbps and low enough latency for constant interactivity. A case study is provided, comparing uncompressed and compressed streaming techniques, with performance evaluations for bandwidth use, total latency, maximum frame rate, and visual quality.     

Advances towards high‐resolution pack‐and‐go displays: A survey

Abstract— Tiled displays provide high resolution and large scale simultaneously. Projectors can project on any available surface. Thus, it is possible to create a large high‐resolution display by simply tiling multiple projectors on any available regular surface. The tremendous advancement in projection technology has made projectors portable and affordable. One can envision displays made of multiple such projectors that can be packed in one's car trunk, carried from one location to another, deployed at each location easily to create a seamless high‐resolution display, and, finally, dismantled in minutes to be taken to the next location — essentially a pack‐and‐go display. Several challenges must be overcome in order to realize such pack‐and‐go displays. These include allowing for imperfect uncalibrated devices, uneven non‐diffused display surfaces, and a layman user via complete automation in deployment that requires no user invention. We described the advances we have made in addressing these challenges for the most common case of planar display surfaces. First, we present a technique to allow imperfect projectors. Next, we present a technique to allow a photometrically uncalibrated camera. Finally, we present a novel distributed architecture that renders critical display capabilities such as self‐calibration, scalability, and reconfigurability without any user intervention. These advances are important milestones towards the development of easy‐to‐use multi‐projector displays that can be deployed anywhere and by anyone.     

Real-time multi-scale brain data acquisition, assembly, and analysis using an end-to-end OptIPuter

At iGrid 2005 we demonstrated the transparent operation of a biology experiment on a test-bed of globally distributed visualization, storage, computational, and network resources. These resources were bundled into a unified platform by utilizing dynamic lambda allocation, high bandwidth protocols for optical networks, a Distributed Virtual Computer (DVC) [N. Taesombut, A. Chien, Distributed Virtual Computer (DVC): Simplifying the development of high performance grid applications, in: Proceedings of the Workshop on Grids and Advanced Networks, GAN 04, Chicago, IL, April 2004 (held in conjunction with the IEEE Cluster Computing and the Grid (CCGrid2004) Conference)], and applications running over the Scalable Adaptive Graphics Environment (SAGE) [L. Renambot, A. Rao, R. Singh, B. Jeong, N. Krishnaprasad, V. Vishwanath, V. Chandrasekhar, N. Schwarz, A. Spale, C. Zhang, G. Goldman, J. Leigh, A. Johnson, SAGE: The Scalable Adaptive Graphics Environment, in: Proceedings of WACE 2004, 23–24 September 2004, Nice, France, 2004]. Using these layered technologies we ran a multi-scale correlated microscopy experiment [M.E. Maryann, T.J. Deerinck, N. Yamada, E. Bushong, H. Ellisman Mark, Correlated 3D light and electron microscopy: Use of high voltage electron microscopy and electron tomography for imaging large biological structures, Journal of Histotechnology 23 (3) (2000) 261–270], where biologists imaged samples with scales ranging from 20X to 5000X in progressively increasing magnification. This allows the scientists to zoom in from entire complex systems such as a rat cerebellum to individual spiny dendrites. The images used spanned multiple modalities of imaging and specimen preparation, thus providing context at every level and allowing the scientists to better understand the biological structures. This demonstration attempts to define an infrastructure based on OptIPuter components which would aid the development and design of collaborative scientific experiments, applications and test-beds and allow the biologists to effectively use the high resolution real estate of tiled displays.     

利用空域采样相移干涉计量法测量微小位移

提出了一种利用空域采样实现相移干涉计量的新方法和实验演示装置。演示装置使用倾斜镜或阶梯镜作为相移器件,线阵CCD做为光学传感器。实验表明:此方法非常适用于测量快速变化的目标或动态过程,其测量精度与传统时域采样相移技术相当但具有更好的稳定性和更高的测量速度,而测量范围是离焦量的2倍。     

Numerical comparison of performance between traditional and alternative jet fans in tiled tunnel in emergency ventilation

In this paper a computational study was carried out to evaluate the performance of longitudinal ventilation system equipped with an alternative jet fan with respect to traditional one in case of fire in tiled tunnel. The alternative jet fan is equipped with inclined silencers (pitch angle α = 6°) in order to reduce the Coanda effect and consequently shear stress on the tunnel ceiling. The fire was simulated setting heat flux on HGV surface. Computational fluid dynamic analysis was applied to simulate the ventilation in the unidirectional tunnel through κ–ɛ model. The comparison conducted in terms of total thrust required to prevent back-layering phenomena and numerical results were provided in terms of thrust of jet fan values, average velocity values and temperature profiles, for different tunnel slope values. Furthermore the authors have compared the critical velocity provided by CFD analysis with critical velocity provided in the literature.     

基于机群的拼贴显示系统的软件结构

利用计算机系统控制多个图形部件,驱动多个投影仪得到基于投影拼贴的显示,是突破现有显示技术制约,实现千万像素以上的高清晰度大尺寸显示的有效手段。目前采用PC机群系统来驱动拼贴显示系统的方式由于其较高的性能价格比正日益成为主流的选择,但是这种实现方式同时需要更复杂的分布式显示软件的支持。该文分析比较了几种基于机群的拼贴显示系统的软件结构并在此基础上提出了一种新的适合并行程序环境的软件接口。     

SimTile:片状多核处理器的高效模拟器(英文)

传统的基于共享总线的多核芯片随着核心数增加产生了瓶颈问题。新型TiledCMP(chip multiprocessor)的结构设计中,片上核心互联网络对提高扩展能力和执行效率起到了重要作用。为了实现低延迟、高带宽的核心通信,高速点对点网络方式的片上多核互联结构模拟成为研究的热点。抽象片上Tiled方式16核功能单元结构,设计实现了SimTile模拟器,可提供配置灵活、功能单元齐全的片上多核处理器设计,支持高效率的全局共享缓存、高速片上路由结构。模拟器采用模块化的组件配置方式,片上核心数量与互联网络结构、数据一致性协议、全局寄存器通信与cache共享模式等,均可通过精简的参数调整。实验表明模拟器执行效率较高,为片上多核研究提供了灵活、高效并具备可扩展性的新平台。     

SAGE-based Tiled Display Wall enhanced with dynamic routing functionality triggered by user interaction

To empower scientists who are engaged in nation-wide or global-scale collaborative projects for scientific discovery, a large amount of scientific data needs to be visualized and then shared among the scientists. Tiled Display Wall (TDW) has been widely accepted and used for visualization of large-scale scientific data. Scalable Adaptive Graphics Environment (SAGE) has received attention from scientists as a middleware that organizes multiple display monitors into a network-aware large display monitor. Using a SAGE TDW, scientists can display multiple visualized contents on a single display monitor, each of which can be located at geographically distant site managed by other organizations. However, SAGE does not have a mechanism for managing multiple visualized data streams heading to a single TDW. In a conventional network, data flows for a same destination tend to share a same link, resulting in drop of packets and therefore poor visual quality. Moreover, because of the flexible nature of SAGE, rate of each visual data flow may change dynamically as a result of user interaction on a TDW, such as moving and resizing an application window. For the reason above, we propose and develop a dynamic route allocation method that switches packet flows onto network links where better performance is expected, in response to user interaction such as window movement and resizing. Technically, we have leveraged OpenFlow, an implementation of Software Defined Networking (SDN), to integrate network programmability into SAGE. In this paper, we show how SAGE enhanced with the proposed method succeeded in avoiding network congestion and improving the quality of visualization on the TDW over the wide area OpenFlow network on the Internet.     

The NRL layered ocean model

We describe the portable scalable implementation of the NRL Layered Ocean Model (NLOM). Scalability is based primarily on the tiled data parallel parallel programming paradigm. This is sufficiently general that the actual technique used on a given machine to obtain scalability can be selected at compile time from: (i) data parallel, (ii) SPMD message passing, (iii) autotasking, or (iv) SPMD message passing between multi-processor autotasked systems. The code is thus portable onto all machine types likely to be used by ocean modelers.