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.
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.
1080078
Reducing Cache Traffic and Energy with Macro Data Load
This paper presents a study on macro data load, an efficient mechanism to enhance loaded value reuse. A macro data load brings into the processor a maximum-width data value the cache port allows, saves it in an internal structure, and facilitates reuse by later loads. A comprehensive limit study using a generalized memory value reuse table (MVRT) shows the significantly increased reuse opportunities provided by macro data load. We also describe a modified load store queue design as an implementation of the proposed concept. Our quantitative study shows that over 35% of L1 cache accesses in the SPEC2k integer and MiBench programs can be eliminated, resulting in a related energy reduction of 24% and 35% on average, respectively
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.
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.
10940298
An Extensible Data Model with Security Support for Dataspace Management
Based on the iDM concept, this paper proposes an extensible data model with an 8-tuple representation, which can not only describe more complex data sources by extending the Group Component, but also contain rule-based security elements, which consist of Access Component and Authorization Component. Data model is detailed and two corresponding examples are analyzed to verify our approach.
1199842
Secure Dataspace with Access Policies
Inspired by rule-based access control models, this paper proposes a universal policy model and an access protection framework to secure dataspace. The key components and processes for this framework, policy organization, policy indexing and two resource searching strategies with access decision-making, are illustrated and experimented to harmonize the contradiction between security and efficiency.