Search results for "Cryptography"
showing 10 items of 657 documents
One-dimensional hydrodynamic modeling of coronal plasmas on transputer arrays
1990
Abstract We describe a concurrent implementation of the Palermo-Harvard hydrodynamic code on cost-effective and modularity expandable transputer arrays. We have tested the effectiveness of our approach by simulating an already well-studied compact solar-flare model on different transputer configurations and compared their performances with those of other machines. We have found that the speed of the concurrent program on a 16-T800 transputers array is ~1/9 of that of the equivalent code optimized for a CRAY X-MP/48. This work clearly shows that transputer-based arrays provide locally available high computing-power tools to extend the investigation of compact solar flares and similar astroph…
On the potential of NoC virtualization for multicore chips
2008
As the end of Moores-law is on the horizon, power becomes a limiting factor to continuous increases in performance gains for single-core processors. Processor engineers have shifted to the multicore paradigm and many-core processors are a reality. Within the context of these multi-core chips, three key metrics point themselves out as being of major importance, performance, fault-tolerance (including yield), and power consumption. A solution that optimizes all three of these metrics is challenging. As the number of cores increases the importance of the interconnection network-on-chip (NoC) grows as well, and chip designers should aim to optimize these three key metrics in the NoC context as …
Tecsis: Low-Cost Methodology To Distinguish Archaeological Findings
2006
The automatic or semi-automatic research of archaeological findings includes some methodologies and algorithms of the Computer Vision. Reconstruction of a scene is one of the key step to get the solution to that challenge. This paper will address a methodology to reconstruction underwater scenes with mosaicing techniques. The reconstruction of scene will be the video-mosaic of sea bottom landscapes starting from single video frames. The methodology is based on the evaluation of the optic °ow in between frames, and its motion estimation has been evaluated on the extracted features from the common areas of consecutive pairs frames. This approach carried out the motion model from a geometric p…
VIBPACK: A package to treat multidimensional electron-vibrational molecular problems with application to magnetic and optical properties
2018
We present a FORTRAN code based on a new powerful and efficient computational approach to solve multidimensional dynamic Jahn-Teller and pseudo Jahn-Teller problems. This symmetry-assisted approach constituting a theoretical core of the program is based on the full exploration of the point symmetry of the electronic and vibrational states. We also report some selected examples of increasing complexity aimed to display the theoretical background as well as the advantages and capabilities of the program to evaluate of the energy pattern, magnetic and optical properties of large multimode vibronic systems. © 2018 Wiley Periodicals, Inc.
Spim-Cache: A Pedagogical Tool for Teaching Cache Memories Through Code-Based Exercises
2007
Cache memories represent a core topic in all computer organization and architecture courses offered at universities around the world. As a consequence, educational proposals and textbooks address important efforts to this topic. A valuable pedagogical help when studying cache memories is to perform exercises based on simple algorithms, which allow the identification of cache accesses, for instance, a program accessing the elements of an array. These exercises, referred to as code-based exercises, have a good acceptance among instructors of computer organization courses. Nevertheless, no tool (e.g., simulator) has been developed to be used in undergraduate courses working with this kind of e…
The Screen Is Yours—Comparing Handheld Pairing Techniques for Public Displays
2013
Whereas mobile devices have been heavily investigated as remote controls for distant displays, research on the fundamental first step, the pairing with the display, is scarce. In a comparative user study with 31 participants we evaluated five potential pairing techniques concerning their performance and acceptance for connecting to a public display and gained insights into the general requirements for pairing techniques in this special usage context. Besides four established mobile interaction techniques (touching an NFC tag, capturing a QR code, scanning, and manual input), our study considered a recent appropriate pairing technique called display pointing, which allows passers-by to conne…
Visualization and User Interface Questions about Disability
1999
The visually impaired and the intellectually disabled are not equal groups but both groups benefit partly from the same features. Communication, symbols, pictures, customizing and alternative languages are the key elements in visualization and in user interface design to the both groups.
Gestural and audio metaphors as a means of control for mobile devices
2002
This paper discusses the use of gesture and non-speech audio as ways to improve the user interface of a mobile music player. Their key advantages mean that users could use a player without having to look at its controls when on the move. Two very different evaluations of the player took place: one based on a standard usability experiment (comparing the new player to a standard design) and the other a video analysis of the player in use. Both of these showed significant usability improvements for the gesture/audio-based interface over a standard visual/pen-based display. The similarities and differences in the results produced by the two studies are discussed
Universal N -Partite d -Level Pure-State Entanglement Witness Based on Realistic Measurement Settings
2019
Entanglement witnesses are operators that are crucial for confirming the generation of specific quantum systems, such as multipartite and high-dimensional states. For this reason, many witnesses have been theoretically derived which commonly focus on establishing tight bounds and exhibit mathematical compactness as well as symmetry properties similar to that of the quantum state. However, for increasingly complex quantum systems, established witnesses have lacked experimental achievability, as it has become progressively more challenging to design the corresponding experiments. Here, we present a universal approach to derive entanglement witnesses that are capable of detecting the presence …
A secret sharing scheme for anonymous DNS queries
2013
Since its adoption in the early 90's, several privacy concerns have emerged about the Domain Name System (DNS). By collecting the DNS queries performed by each user, it is possible to characterize habits, interests and other sensitive data of the users. Usually, users resolve their {\em url} requests by querying the DSN server belonging to their Internet Service Provider (ISP) and therefore they assume they can trust it. However, different DNS servers can be used, by revealing sensitive data to a partially untrusted entity that can collect and sell this data for several purposes (target advertising, user profiling, etc.). In this paper we address the possibility to integrate tools in the cu…