Tiling Technique Research Articles

Low-overhead fault-tolerance technique for a dynamically reconfigurable softcore processor

In this paper, we propose a new approach to implement a reliable softcore processor on SRAM-based FPGAs, which can mitigate radiation-induced temporary faults (single-event upsets (SEUs)) at moderate cost. A new Enhanced Lockstep scheme built using a pair of MicroBlaze cores is proposed and implemented on Xilinx Virtex-5 FPGA. Unlike the basic lockstep scheme, ours allows to detect and eliminate its internal temporary configuration upsets without interrupting normal functioning. Faults are detected and eliminated using a Configuration Engine built on the basis of the PicoBlaze core which, to avoid a single point of failure, is implemented as fault-tolerant using triple modular redundancy (TMR). A softcore processor can recover from configuration upsets through partial reconfiguration combined with roll-forward recovery. SEUs affecting logic which are significantly less likely than those affecting configuration are handled by checkpointing and rollback. Finally, to handle permanent faults, the tiling technique is also proposed. The new Enhanced Lockstep scheme requires significantly shorter error recovery time compared to conventional lockstep scheme and uses significantly smaller number of slices compared to known TMR-based design (although at the cost of longer error recovery time). The efficiency of the proposed approach was validated through fault injection experiments.

Viewing-angle enlargement in holographic augmented reality using time division and spatial tiling

Viewing angle enlargement is essential for SLM-based 3D holographic display. An idea of constructing equivalent-curved-SLM-array (ECSA) is proposed by linear phase factor superimposition. Employing the time division and spatial tiling (TDST) techniques, an ECSA-based horizontal 4f optical system is designed and built. The horizontal viewing angle of a single SLM is increased to 3.6 times when retaining the same hologram area. An interlaced holographic display technique is developed to remove the flicker effect. Holographic augmented reality is performed using the TDST system. Floating holographic 3D image with parallax and accommodation effects is achieved. Both TDST and interlaced technique may extend to multiple SLMs system to achieve larger viewing angle.

Investigation into lossless hyperspectral image compression for satellite remote sensing

Hyperspectral sensors acquire images in many, very narrow, contiguous spectral bands throughout the visible, near-infrared (IR), mid-IR and thermal IR portions of the spectrum, thus requiring large data storage on board the satellite and high bandwidth of the downlink transmission channel to ground stations. Image compression techniques are required to compensate for the limitations in terms of on-board storage and communication link bandwidth. In most remote-sensing applications, preservation of the original information is important and urges studies on lossless compression techniques for on-board implementation. This article first reviews hyperspectral spaceborne missions and compression techniques for hyperspectral images used on board satellites. The rest of the article investigates the suitability of the integer Karhunen–Loève transform (KLT) for lossless inter-band compression in spaceborne hyperspectral imaging payloads. Clustering and tiling strategies are employed to reduce the computational complexity of the algorithm. The integer KLT performance is evaluated through a comprehensive numerical experimentation using four airborne and four spaceborne hyperspectral datasets. In addition, an implementation of the integer KLT algorithm is ported to an embedded platform including a digital signal processor (DSP). The DSP performance results are reported and compared with the desktop implementation. The effects of clustering and tiling techniques on the compression ratio and latency are assessed for both desktop and the DSP implementation.

Efficient parallel implementation of incompressible pipe flow algorithm based on SIMPLE

SummaryParallel semi‐implicit method for pressure‐linked equations(SIMPLE) algorithm is used to solve the 3‐D incompressible pipe flow problem. In this paper, we proposed a novel parallel SIMPLE algorithm that uses the alternate tiling technique. Firstly, a parallel SIMPLE algorithm based on domain decomposition method was established, and the implementation of domain partition and data exchange was presented. Then, we presented serial finite difference stencil algorithm based on alternate tiling. Furthermore, an iteration space parallel two‐way finite difference stencil algorithm based on alternate tiling was proposed, introducing the sequence of iterative space tiles as the sequence of execution and using time skewing technique to partition the iteration space, thus to improve the data locality of algorithm. The cache misses and the cost of communication and synchronization are reduced by reordering the tiles of iteration space. Finally, the effectiveness of the two parallel SIMPLE algorithms were compared. The results showed that the parallel SIMPLE algorithm that uses the two‐way finite difference stencil algorithm based on alternate tiling has good data locality, performance, and scalability in the Deepcomp7000 cluster computing environment. Copyright © 2013 John Wiley & Sons, Ltd.

The Glazed Tile Techniques of the Seljuk and Beylik Periods

The word “tile” originates from Persian and means “China” or “Chinese work”. In the Ottoman language, the word “tile” also means “Chinese work”, or “belonging to China”. The art of Turkish tiles occupies a place of prominence in the history of Islamic art. Its roots can be traced at least as far back as the Uygurs of the eighth and ninth centuries. Its subsequent development was influenced by the Karakhanids, the Ghaznavids, and (especially) Iranian Seljuk art. With the Seljuks’ victory over the Byzantines at Malazgirt in 1071, the art followed them into Anatolia and embarked upon a new period of strong development fostered by the Anatolian Seljuk sultanate. The first major development in the art of tile-making occurred primarily in Anatolian Seljuk architecture. Various techniques have been used in the art of tiles which gave hundreds of samples for centuries. This study explores the glazed tile techniques used in the production of the Seljuk and Beylik periods.

FPGA based Implementation of High Speed Double Precision Floating Point Multiplier with Tiling Technique using Verilog

Floating point arithmetic is widely used in many areas, especially scientific computation and signal processing. For many signal processing, and graphics applications, it is acceptable to trade off some accuracy (in the least significant bit positions) for faster and better implementations. However, most of these modern applications need higher frequency or low latency of operations with minimal area occupancy. In this paper we describe an implementation of high speed IEEE 754 double precision floating point multiplier using tiling technique and targeted for Xilinx Virtex-6 Field Programmable Gate Array. Verilog is used to implement the design. The design achieved 436.815 MFlops with latency of seven clock cycles which is 97% fast compared to Xilinx floating point multiplier core. It handles the overflow, underflow cases and truncation rounding mode.

Combinatorial Proofs of Some Identities for Nonregular Continued Fractions

A combinatorial interpretation of nonregular continued fractions is studied. Using a modification of a tiling technique due to Benjamin and Quinn, combinatorial proofs of some identities for nonregular continued fractions are obtained.

Parallelizing SOR for GPGPUs using alternate loop tiling

Gauss-Seidel and SOR, which are widely used smoothers in multigrid methods, are difficult to parallelize, particularly on GPGPUs due to the existence of DOACROSS data dependences. In this paper, we present a new parallel SOR method that admits more efficient data-parallel SIMD execution than red-black SOR on GPGPUs. Our solution is obtained non-conventionally, by starting from a K-layer SOR method and then parallelizing it by applying a non-dependence-preserving scheme consisting of a new domain decomposition technique followed by a loop tiling technique called alternate tiling. Despite its relatively slower convergence, our new method outperforms red-black SOR by making a better balance between data reuse and parallelism and by trading off convergence rate for SIMD parallelism. Our experimental results highlight the importance of synergy between domain experts, compiler optimizations and performance tuning in maximizing the performance of PDE-like DOACROSS loops on GPGPUs.

A hierarchical organization approach of multi-dimensional remote sensing data for lightweight Web Map Services

With the rapid development of the World Wide Web, remote sensing (RS) data have become available to a wider range of public/professional users than ever before. Web Map Services (WMSs) provide a simple Web interface for requesting RS data from distributed geospatial databases. RS data providers typically expect to provide lightweight WMSs. They have a low construction cost, and can be easily managed and deployed on standard hardware/software platforms. However, existing systems for WMSs are often heavyweight and inherently hard to manage, due to their improper usage of databases or data storage. That is, they are not suitable for public data services on the Web. In addition, RS data are moving toward the multi-dimensional paradigm, which is characterized by multi-sensor, multi-spectral, multi-temporal and high resolution. Therefore, an efficient organization and storage approach of multi-dimensional RS data is needed for lightweight WMSs, and the efficient WMSs must support multi-dimensional Web browsing. In this paper, we propose a Global Remote Sensing Data Hierarchical Model (GRHM) based on the image pyramid and tiling techniques. GRHM is a logical model that is independent upon physical storage. To support lightweight WMSs, we propose a physical storage structure, and deploy multi-dimensional RS data on Web servers. To further improve the performance of WMSs, a data declustering method based on Hilbert space-filling curve is adopted for the distributed storage. We also provide an Open Geospatial Consortium (OGC) WMS and a Web map system in Web browsers. Experiments conducted on real RS datasets show promising performance of the proposed lightweight WMSs.

A Framework of Information Technology for Water Resources Management

use of the information technology in internet GIS, Remote Sensing data and World Wide Web in most of the research works relating geosciences and public is indispensable. As the nodal data banks and public utility are ever evolving along with the technological advancements, it is necessary to have an interoperable linked geospatial infrastructure for surface as well as underground water resources. IWML (India Water-resources Markup Language) is proposed for the monitoring of surface and subsurface water resources data of India. IWML works on Asynchronous java Script and XML and image tiling can improve the performance and response time of Internet GIS application significantly. A framework of IWML and image tiling techniques for Web-based visualization for water resources management is discussed. Functioning of the web- oriented water resources information requires a leadership and management support, technical architecture, creating and sharing water resources data, adoption of standards, creation and support of community water data portals and ongoing participation. It serves the multidisciplinary users at diverse applications such as map viewing, query answering, simple mashup's analysis and visualization, customized applications for particular purposes, access to server side modeling, data discovery download for local analysis and developing a common operating dashboard for situational awareness. Water information integration with web GIS, Google, and Satellite will improve the user's ability to integrate, plan, manage and design more holistically the water resources systems.

Parallel and efficient Boolean on polygonal solids

We present a novel framework which can efficiently evaluate approximate Boolean set operations for B-rep models by highly parallel algorithms. This is achieved by taking axis-aligned surfels of Layered Depth Images (LDI) as a bridge and performing Boolean operations on the structured points. As compared with prior surfel-based approaches, this paper has much improvement. Firstly, we adopt key-data pairs to store LDI more compactly. Secondly, robust depth peeling is investigated to overcome the bottleneck of layer-complexity. Thirdly, an out-of-core tiling technique is presented to overcome the limitation of memory. Real-time feedback is provided by streaming the proposed pipeline on the many-core graphics hardware.

Efficient and Scalable Routing Algorithms for Collective Communication Operations on 2D All-Port Torus Networks

Collective Communication Algorithms for 2D torus networks have been investigated quite extensively in the literature and two broad approaches, namely direct methods and indirect (message combining) methods are recognized in the field. While direct methods minimize the volume of data, the indirect methods reduce the number of message start-ups. Consequently, either a suite of algorithms must be employed for efficiency over a wide range of message lengths and communication operations or algorithms should be able to adapt themselves to the current case, possibly by switching between direct and indirect routing modes as appropriate. In this paper, we propose adaptive routing algorithms for all-port, wormhole routed, synchronous, 2D torus networks optimized for one-to-all broadcast, gossiping and complete exchange collective communication operations. The proposed algorithms employ completely-connected subnetworks where complete exchange amongst the nodes in the subnetwork can be accomplished in one step only. Combined with suitable 2D plane tiling techniques, the proposed algorithms share the same set of primitive operations and yield superior performance compared to previously proposed methods, either pure or hybridized.

Tiling in My Music

Rhythmic canons and other one-dimensional tiling techniques dominated my composing for two or three years, and a number of instrumental pieces, both solo and ensemble, evolved during this time. With numerous examples, I have put together a little survey of different ways in which I have done this, often leaving holes and using other procedures not normally considered correct. It must have been 1999 when Moreno Andreatta gave me a copy of Dan Tudor Vuza’s landmark essay Supplementary Sets and Regular Complementary Unending Canons (Perspectives of New Music, 1991-92), because already in 2000 its influence on me became clear with a Canon in 3, 6 or 9 voices, written for an installation of Martin Riches in Berlin. When the MaMuX meetings at IRCAM began in 2001, I was able to hear regularly the mathematical music theories of Guerino Mazzola, Thomas Noll, Emmanuel Amiot, Franck Jedrzejewski and Harald Fripertinger, as well as Andreatta himself and many occasional visitors, and this information stimulated me more and more. My composing time during the year 2002 was devoted almost exclusively to fitting together little rhythmic tiles, and early in 2003 I brought out the edition Tiilework : 14 Pieces for 14 Solo Instruments. Later that year I wrote Tilework for String Quartet, and Tilework for Piano, though by the end of that year my concentration was already turning more toward combinatorial designs, which is quite a different topic. I recently reread the Vuza essay, and it seems all the more clear to me that this text has been important for all the mathematicians and music theorists cited above, not to mention for Jon Wild and other North American music theorists, and for quite a few composers. I now consider this work the most important music theory treatise of the last 20 years, particularly since it is one of those rare cases where music theory has preceded musical practice. Harmony and counterpoint books, essays on serial techniques, manuals for figured bass, and music analysis texts have generally dealt exclusively with musical procedures already practiced by composers. Only in rare cases like Vuza, Leonhard Euler, and Hugo Riemann have theorists preceded composers, though Henry Cowell’s 1930 book New Musical Resources should also be mentioned. This highly original text never circulated much in Europe, but it was widely read in the U.S. The author never followed up on these theories much in his own music, but John Cage and Conlon Nancarrow both sited this as a seminal influence on their music, and younger American composers such as Kyle Gann, Larry Polanskyn, David First, and John Luther Adams also acknowledge the

Multipliers for floating-point double precision and beyond on FPGAs

The implementation of high-precision floating-point applications on reconfigurable hardware requires large multipliers. Full multipliers are the core of floating-point multipliers. Truncated multipliers, trading resources for a well-controlled accuracy degradation, are useful building blocks in situations where a full multiplier is not needed. This work studies the automated generation of such multipliers using the embedded multipliers and adders present in the DSP blocks of current FPGAs. The optimization of such multipliers is expressed as a tiling problem, where a tile represents a hardware multiplier, and super-tiles represent combinations of several hardware multipliers and adders, making efficient use of the DSP internal resources. This tiling technique is shown to adapt to full or truncated multipliers. It addresses arbitrary precisions including single, double but also the quadruple precision introduced by the IEEE-754-2008 standard and currently unsupported by processor hardware. An open-source implementation is provided in the FloPoCo project.

Tiled Composite Laminates

This article describes our efforts to develop a meso-scale in-plane tiling technique for fiber-reinforced composite laminates. Such a technique expands the design space of the laminate, and the ability to tailor local laminate properties may provide a means, for example, to mitigate stress concentrations that arise in places such as along free edges of the laminate. Preliminary fabrication of tiled laminates produced material with an elastic modulus that is nearly equal to that of continuously reinforced laminates; however, the strength of these first specimens was significantly reduced. Finite element analyses were then performed to characterize the effects of features unique to tiled composite laminates, such as the existence of resin-rich tile-to-tile interfaces, and to explore the effects of relative arrangement of tiles through the thickness of the laminate. This led to a novel composite joint geometry as well as recommendations to minimize strength reduction. Strength retention of laminates fabricated using the new design guidelines was experimentally found to exceed 92% in comparison with the traditional analogs. Finally, we discuss the potential application of composite tiling for the suppression of free-edge delamination.

Efficient algorithms for self assembling non-rectangular nano structures

Nano fabrication with biomolecular/DNA self assembly is a promising area of research. Building nano structures with self assembly is both efficient and inexpensive. Soloveichik and Winfree (SIAM J Comput 36(6):1544---1569, 2007) formalized a two dimensional (2D) tile assembly model based on Wang's tiling technique. Algorithms with an optimal tile complexity of $$\left(\Uptheta\left(\frac{\log(N)}{\log(\log(N))}\right)\right)$$ were proposed earlier to uniquely self assemble an N × N square (with a temperature of ? = 2) on this model. However efficient constructions to assemble arbitrary shapes are not known and have remained open. In this paper we present self assembling algorithms to assemble a triangle of base 2N ? 1 (units) and height N with a tile complexity of $$\Uptheta(\log(N)).$$ We also describe how this framework can be used to construct other shapes such as rhombus, hexagon etc.

イメージセンサチップ実装時の反り低減技術

We have developed a technique to reduce the chip warpage that results when a large sensor chip is bonded to a board. We performed a structure simulation that included the use of die-bond resins. We improved the die-bonding process, produced a prototype, and tested it. Results showed that it is possible to keep the warpage below 20μm even when a chip over 20 mm long is bonded to a printed circuit board with thermoset die-bond resins. We used our warp control technique to bend a sensor chip in the direction of the field curvature of a photographic lens. With the aim of deploying large sensors in the future, we performed a basic verification test of the tiling technique used to align multiple chips in a plane, developed a chip connection technique, and identified potential problems that could hamper the practical use of both.

Dividing Virtual Belt Algorithm for Reconstructing Surface from a Set of Wire-Frame Contours

A new mesh reconstruction technique, called dividing virtual belt algorithm (DVBA), is proposed for approximating the surface from a set of wire-frame contours. DVBA decomposes the branching region into a set of virtual belts and virtual canyons. A tiling technique based on the divide-and-conquer strategy is also introduced to approximate the surface from the virtual belt, and the virtual canyons are covered by a conventional polygon triangulation technique. The experimental result shows that our method works well even though there are many complicated branches in the object.

Brane tilings for orientifolds

AbstractWe give an elementary introduction to the recent derivation of the effective low‐energy gauge theories of D3‐branes probing orientifolds of toric Calabi‐Yau 3‐fold singularities via brane tiling techniques.

The UK National External Quality Assessment Scheme in Blood Group Serology. Compatibility testing 1979-1980: trends and performance in relation to practice in antiglobulin testing

Surveys of antiglobulin test procedures and reagents were undertaken in 1979-1980 as part of a national external quality assessment scheme in compatibility testing. An extraordinary lack of standardization was revealed. In addition, practices underwent considerable changes over this period. The use of tube and of low ionic strength solution (LISS) techniques increased whilst the use of tile and of albumin-antiglobulin techniques declined. Performance in compatibility test exercises was significantly better with tube techniques than with tile techniques in 9/22 incompatibilities. Performance with LISS techniques was occasionally significantly better than with normal ionic strength techniques. Performance with albumin-antiglobulin techniques was occasionally significantly worse than in the absence of albumin. To varying extents significant relationships were found between performance and cell concentration, serum/cell concentration ratio, antiglobulin reagent and method of reading the results.