2,725 research outputs found

    An Efficient Data Structure for Dynamic Two-Dimensional Reconfiguration

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    In the presence of dynamic insertions and deletions into a partially reconfigurable FPGA, fragmentation is unavoidable. This poses the challenge of developing efficient approaches to dynamic defragmentation and reallocation. One key aspect is to develop efficient algorithms and data structures that exploit the two-dimensional geometry of a chip, instead of just one. We propose a new method for this task, based on the fractal structure of a quadtree, which allows dynamic segmentation of the chip area, along with dynamically adjusting the necessary communication infrastructure. We describe a number of algorithmic aspects, and present different solutions. We also provide a number of basic simulations that indicate that the theoretical worst-case bound may be pessimistic.Comment: 11 pages, 12 figures; full version of extended abstract that appeared in ARCS 201

    Maintaining a frozen shipping environment for Phase I clinical trial distribution

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    The need for stringent temperature control provides significant challenges to pharmaceutical distributors operating in all sectors of the industry. Products with a frozen storage label requirement can be significantly problematic. This study aimed to provide evidence of robust and reproducible frozen shipment arrangements to be operated by a Phase I clinical trial unit. Dry ice was used to achieve a deep frozen internal parcel environment and was tested in a laboratory setting using ultra low temperature loggers within dummy product packs within the test parcels. The laboratory dry ice packing configuration was then repeatedly tested in real time transits using a Glasgow to London delivery schedule. An internal temperature specification was set to not exceed −10 °C during the transport. During each delivery, external temperature monitoring measured the temperature stress experienced by the box in transit. Results demonstrated the ability of the chosen system to not exceed −13.6 °C on average (−10 °C maximum) when exposed to external temperatures of up to +20.1 °C (mean kinetic temperature). The effect was maintained for at least 52.5 h

    Rapid prototyping of plastic lab-on-a-chip by femtosecond laser micromachining and removable insert microinjection molding

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    We have introduced a new hybrid fabrication method for lab-on-a-chip devices through the combination of femtosecond laser micromachining and removable insert micro-injection molding. This method is particularly suited for the fast prototyping of new devices, while maintaining a competitive low cost. To demonstrate the effectiveness of our approach, we designed, fabricated, and tested a completely integrated flow cytometer coupled to a portable media device. The system operation was tested with fluorescent plastic micro-bead solutions ranging from 100 beads/?L to 500 beads/?L. We demonstrated that this hybrid lab-on-a-chip fabrication technology is suitable for producing low-cost and portable biological microsystems and for effectively bridging the gap between new device concepts and their mass production

    NSSDC Conference on Mass Storage Systems and Technologies for Space and Earth Science Applications, volume 1

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    Papers and viewgraphs from the conference are presented. This conference served as a broad forum for the discussion of a number of important issues in the field of mass storage systems. Topics include magnetic disk and tape technologies, optical disks and tape, software storage and file management systems, and experiences with the use of a large, distributed storage system. The technical presentations describe, among other things, integrated mass storage systems that are expected to be available commercially. Also included is a series of presentations from Federal Government organizations and research institutions covering their mass storage requirements for the 1990's

    Comparison of Strengths Between Acrylic Resin Prosthetics with Thermoplastic Acrylic Against Charpy Impact on Artificial Dental Manufacturing

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    Heat-cured acrylic resin is the most widely used base material to manufacture removable dentures. Because it has aesthetic advantages, is non-toxic, does not irritate the oral mucosa, is inexpensive, and is easy to manipulate and repair. However, this material has drawbacks. Namely, it has microporosity to absorb liquid, and it is easy to fracture if hit on a hard surface or under prolonged use. This study aimed to determine the difference in impact strength between heat-cured acrylic and thermoplastic acrylic against Charpy impact (impact pressure). It can be used as the basis for adding wire or metal plates to increase the material's mechanical strength. This type of research is an experimental laboratory experiment to determine specific treatments' effects. The research samples were heat cured acrylic and thermoplastic acrylic plates with a size of 65 mm x 10 mm x 2.5 mm according to ADA specification no. 12, totaling 16 pieces for each group. The sample criteria are in the form of blocks according to the size, which is smooth and shiny. Data analysis used the One Way Anova and Least Significant Difference test to see the impact strength of heat cured acrylic plate compared to the thermoplastic acrylic plate with a significance level (p=0.05). One Way Anova test results obtained p< 0.05, proving a significant difference between the Heat Cured Acrylic Resin group and the Acrylic Thermoplastic group. The Least Significant Difference calculation results show that the average difference between Heat Cured Acrylic Resin and Thermoplastic Acrylic is 56.8. It is greater than the LSD calculation of 9.802465, which means there is a significant difference between the average Heat Cured Acrylic Resin and Thermoplastic Acrylic. In conclusion, Heat Cured Acrylic Resin plate has a lower impact strength than Thermoplastic Acrylic

    Online algorithms for 1-space bounded multi dimensional bin packing and hypercube packing

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    In this paper, we study 1-space bounded multi-dimensional bin packing and hypercube packing. A sequence of items arrive over time, each item is a d-dimensional hyperbox (in bin packing) or hypercube (in hypercube packing), and the length of each side is no more than 1. These items must be packed without overlapping into d-dimensional hypercubes with unit length on each side. In d-dimensional space, any two dimensions i and j define a space P ij. When an item arrives, we must pack it into an active bin immediately without any knowledge of the future items, and 90 {ring operator}-rotation on any plane P ij is allowed. The objective is to minimize the total number of bins used for packing all these items in the sequence. In the 1-space bounded variant, there is only one active bin for packing the current item. If the active bin does not have enough space to pack the item, it must be closed and a new active bin is opened. For d-dimensional bin packing, an online algorithm with competitive ratio 4 d is given. Moreover, we consider d-dimensional hypercube packing, and give a 2 d+1-competitive algorithm. These two results are the first study on 1-space bounded multi dimensional bin packing and hypercube packing. © 2012 The Author(s).published_or_final_versionSpringer Open Choice, 28 May 201

    Influence of the feeding mechanism on deposits of square particles

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    In a previous paper [Hidalgo et al., Phys. Rev. Lett. 103, 118001 (2009)] it was shown that square particles deposited in a silo tend to align with a diagonal parallel to the gravity, giving rise to a deposit with very particular properties. Here we explore, both experimentally and numerically, the effect on these properties of the filling mechanism. In particular, we modify the volume fraction of the initial configuration from which the grains are deposited. Starting from a very dilute case, increasing the volume fraction results in an enhancement of the disorder in the final deposit characterized by a decrease of the final packing fraction and a reduction of the number of particles oriented with their diagonal in the direction of gravity. However, for very high initial volume fractions, the final packing fraction increases again. This result implies that two deposits with the same final packing fraction can be obtained from very different initial conditions. The structural properties of such deposits are analyzed, revealing that, although the final volume fraction is the same, their micromechanical properties notably differ
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