2578172
A flexible data to L2 cache mapping approach for future multicore processors
This paper proposes and studies a distributed L2 cache management approach through page-level data to cache slice mapping in a future processor chip comprising many cores. L2 cache management is a crucial multicore processor design aspect to overcome non-uniform cache access latency for high program performance and to reduce on-chip network traffic and related power consumption. Unlike previously studied "pure" hardware-based private and shared cache designs, the proposed OS-microarchitecture approach allows mimicking a wide spectrum of L2 caching policies without complex hardware support. Moreover, processors and cache slices can be isolated from each other without hardware modifications, resulting in improved chip reliability characteristics. We discuss the key design issues and implementation strategies of the proposed approach, and present an experimental result showing the promise of it.
62667888
Two-phase trace-driven simulation (TPTS): a fast multicore processor architecture simulation approach
Simulation is indispensable in computer architecture research. Researchers increasingly resort to detailed architecture simulators to identify performance bottlenecks, analyze interactions among different hardware and software components, and measure the impact of new design ideas on the system performance. However, the slow speed of conventional execution-driven architecture simulators is a serious impediment to obtaining desirable research productivity. This paper describes a novel fast multicore processor architecture simulation framework called Two-Phase Trace-driven Simulation (TPTS), which splits detailed timing simulation into a trace generation phase and a trace simulation phase. Much of the simulation overhead caused by uninteresting architectural events is only incurred once during the cycle-accurate simulation-based trace generation phase and can be omitted in the repeated trace-driven simulations. We report our experiences with tsim, an event-driven multicore processor architecture simulator that models detailed memory hierarchy, interconnect, and coherence protocol based on the TPTS framework. By applying aggressive event filtering, tsim achieves an impressive simulation speed of 146 millions of simulated instructions per second, when running 16-thread parallel applications. Copyright © 2010 John Wiley & Sons, Ltd.
7700541
A comparison of search patterns for cooperative robots operating in remote environment
In this paper, two scanning paradigms are presented and compared that may be used for robotic scanning of a harsh environment such as a celestial body or earth poles. The first paradigm, tight scanning, includes three algorithms, which may be used to find small objects or gasses confined to small regions such as the methane gas given off by bacteria in buried hot springs in the Canadian arctic. The second paradigm, relaxed scanning, includes four algorithms which may be used to find large objects such as large ice deposits that may be buried just below the surface of Mars. The algorithms are compared against their peer algorithms by their quality of performance. Such performance quality is determined by the ratio of scanned area to the traveled distance by the two robots.
60552525
Simulation model of the LS-DRMTA adaptive algorithm for multiple antenna system for DS-CDMA
We present the development of a simulation model and for a conceptual DS-CDMA system and simulation baseband models for the least-square despread respread multitarget array (LS-DRMTA) algorithm with two, four and six antenna elements in the Matlab/Simulink environment. The models are used to compare the performance of single and multiple adaptive antenna systems in an AWGN channel. The simulation models show the clear advantage of multiple antenna systems and represent a first step towards their implementation on an FPGA platform.
46206821
A rule-based system for localization of water on the surface of Mars
In order to use autonomous robots to search for water on the Martian surface, several concerns are raised that need to be addressed, analyzed and remedied. These concerns include the development of a suitable scanning algorithm, positioning system, and obstacle handling. We investigate the above mentioned concerns and propose remedies for them. Also, the remedies are tested by a simulation process. The results convey that the proposed solutions for the raised concerns are effective.
41633714
Electrical and compositional properties of TaSi2 films
Tantalum silicide (TaSi2) thin films were sputter deposited on p- and n-type silicon substrates using ultrapure TaSi2 targets. The TaSi2/Si samples were annealed in nitrogen or forming gas or oxygen containing steam at temperatures in the range of 400–900°C. The sheet resistances of TaSi2/Si were measured by four-point probe before and after anneal. The structure of these films was investigated using x-ray diffraction (XRD) methods. It has been found that the sheet resistance decreases with the increase in annealing temperature and also with the increase in film thickness. X-ray diffraction patterns show changes in the morphological structure of the films. Oxidation characteristics of the film have been investigated in the temperature range of 400–900°C in oxygen containing steam ambient. The oxidation time ranged from 0.5 to 1.5 h. No oxide formation of the tantalum silicide films was observed in this investigation. This has been attributed to the high purity of TaSi2 sputter targets used in the preparation of the films.
18233801
Content-based blind compensation and shaping for streaming video
This paper studies video streaming system over a wireless medium. The major challenge is to provide a robust link along the transmission/transport path and most importantly through noisy channels/networks that could add or drop bytes by unforeseeable factors. As a remedy for this phenomenon, we combine forward error correction, blind compensation and traffic shaping to improve the over all performance. We report on the experiments on this unique performance improvement method. The results of our study can find applications in WiMax and AVCP.