Institution
Worcester Polytechnic Institute
Education•Worcester, Massachusetts, United States•
About: Worcester Polytechnic Institute is a education organization based out in Worcester, Massachusetts, United States. It is known for research contribution in the topics: Computer science & Population. The organization has 6270 authors who have published 12704 publications receiving 332081 citations. The organization is also known as: WPI.
Topics: Computer science, Population, Data envelopment analysis, Nonlinear system, Finite element method
Papers published on a yearly basis
Papers
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TL;DR: This contribution proposes arithmetic architectures which are optimized for modern field programmable gate arrays (FPGAs) that perform modular exponentiation with very long integers, at the heart of many practical public-key algorithms such as RSA and discrete logarithm schemes.
Abstract: It is widely recognized that security issues will play a crucial role in the majority of future computer and communication systems. Central tools for achieving system security are cryptographic algorithms. This contribution proposes arithmetic architectures which are optimized for modern field programmable gate arrays (FPGAs). The proposed architectures perform modular exponentiation with very long integers. This operation is at the heart of many practical public-key algorithms such as RSA and discrete logarithm schemes. We combine a high-radix Montgomery modular multiplication algorithm with a new systolic array design. The designs are flexible, allowing any choice of operand and modulus. The new architecture also allows the use of high radices. Unlike previous approaches, we systematically implement and compare several variants of our new architecture for different bit lengths. We provide absolute area and timing measures for each architecture. The results allow conclusions about the feasibility and time-space trade-offs of our architecture for implementation on commercially available FPGAs. We found that 1,024-bit RSA decryption can be done in 3.1 ms with our fastest architecture.
196 citations
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TL;DR: DLVO calculations based on conventional and soft-particle DLVO theories predicted higher energy barriers to adhesion for all surfaces after LPS removal, consistent with experimental findings.
Abstract: The role of lipopolysaccharides (LPS) in bacterial adhesion was investigated via atomic force microscopy (AFM). Adhesion between a silicon nitride tip and Escherichia coli JM109 was measured in water and 0.01 M phosphate-buffered saline (PBS) on untreated cells and on a sample of E. coli treated with 100 mM ethylenediaminetetraacetic acid (EDTA), which removes approximately 80% of the LPS molecules. LPS removal decreased the adhesion affinity between the bacterial cells and the AFM tip from -2.1 +/- 1.8 to -0.40 +/- 0.36 nN in water and from -0.74 +/- 0.44 to -0.46 +/- 0.23 nN in 0.01 M PBS (statistically different, Mann-Whitney rank sum test, P < 0.01). The distributions of adhesion affinities between E. coli LPS macromolecules and the AFM tip could be described by gamma distribution functions. Direct measurements of the adhesive force between E. coil and a surface were compared with adhesion in batch and column experiments, and agreement was observed between the influences of LPS on adhesion in each system. Bacterial batch retention to glass or in packed beds to quartz sand decreased after LPS removal. When interaction forces were measured during the approach of the AFM tip to a bacterium, steric repulsive forces were seen for both treated and untreated cells, but the repulsion was greater when the LPS was intact A model for steric repulsion predicted a reduction of the equilibrium length of the surface polymers from 242 to 64 nm in water and from 175 to 81 nm in buffer, after removal of a portion of the LPS. DLVO calculations based on conventional and soft-particle DLVO theories predicted higher energy barriers to adhesion for all surfaces after LPS removal, consistent with experimental findings. Adhesion forces between the AFM tip and bacterial polymers were correlated with bacterial attachment and retention, while measurements of interaction forces during the approach of the AFM tip to the bacterium did not correlate with subsequent adhesion behavior to glass or quartz sand.
195 citations
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TL;DR: In this paper, the authors derived the void fraction as a function of particle-to-tube diameter ratio for equilateral hollow cylinders and equilateral solid cylinders, provided a correction factor is included that allows for internal voidage and interpenetration of packings.
Abstract: Correlations have been derived, by both geometrical arguments and empirical treatment of data, for the bulk void fraction in a fixed bed. The void fraction has been correlated as a function of particle-to-tube diameter ratio for packings of spheres and equilateral solid cylinders. Prediction of void fraction for equilateral hollow cylinders can be made from the solid cylinder correlation, provided a correction factor is included that allows for internal voidage and interpenetration of packings.
194 citations
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06 Nov 2019
TL;DR: It is shown that Meltdown-like attacks are still possible, and software fixes with potentially significant performance overheads are still necessary to ensure proper isolation between the kernel and user space.
Abstract: Meltdown and Spectre enable arbitrary data leakage from memory via various side channels. Short-term software mitigations for Meltdown are only a temporary solution with a significant performance overhead. Due to hardware fixes, these mitigations are disabled on recent processors. In this paper, we show that Meltdown-like attacks are still possible on recent CPUs which are not vulnerable to Meltdown. We identify two behaviors of the store buffer, a microarchitectural resource to reduce the latency for data stores, that enable powerful attacks. The first behavior, Write Transient Forwarding forwards data from stores to subsequent loads even when the load address differs from that of the store. The second, Store-to-Leak exploits the interaction between the TLB and the store buffer to leak metadata on store addresses. Based on these, we develop multiple attacks and demonstrate data leakage, control flow recovery, and attacks on ASLR. Our paper shows that Meltdown-like attacks are still possible, and software fixes with potentially significant performance overheads are still necessary to ensure proper isolation between the kernel and user space.
193 citations
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TL;DR: In this paper, a decision-making tool for supplier selection in public procurement is proposed to help the awarding committee in this difficult task and, at the same time, maintaining a transparent procedure in accordance with governmental procurement regulations and requirements as well as guaranteeing fair and equal evaluation of all bids.
192 citations
Authors
Showing all 6336 results
Name | H-index | Papers | Citations |
---|---|---|---|
Andrew G. Clark | 140 | 823 | 123333 |
Ming Li | 103 | 1669 | 62672 |
Joseph Sarkis | 101 | 482 | 45116 |
Arthur C. Graesser | 95 | 614 | 38549 |
Kevin J. Harrington | 85 | 682 | 33625 |
Kui Ren | 83 | 501 | 32490 |
Bart Preneel | 82 | 844 | 25572 |
Ming-Hui Chen | 82 | 525 | 29184 |
Yuguang Fang | 79 | 572 | 20715 |
Wenjing Lou | 77 | 311 | 29405 |
Bernard Lown | 73 | 330 | 20320 |
Joe Zhu | 72 | 231 | 19017 |
Y.S. Lin | 71 | 304 | 16100 |
Kevin Talbot | 71 | 268 | 15669 |
Christof Paar | 69 | 399 | 21790 |