18399312
Power-Conscious Configuration Cache Structure and Code Mapping for Coarse-Grained Reconfigurable Architecture
Coarse-grained reconfigurable architecture aims to achieve both performance and flexibility. However, power consumption is no less important for the reconfigurable architecture to be used as a competitive processing core in embedded systems. In this paper, we show how power is consumed in a typical coarse-grained reconfigurable architecture. Based on the power breakdown data, we suggest a power-conscious configuration cache structure and code mapping technique, which reduce power consumption without performance degradation. Experimental results show that the proposed approach saves much power even with reduced configuration cache size
1907049
A spatial mapping algorithm for heterogeneous coarse-grained reconfigurable architectures
In this work, we investigate the problem of automatically mapping applications onto a coarse-grained reconfigurable architecture and propose an efficient algorithm to solve the problem. We formalize the mapping problem and show that it is NP-complete. To solve the problem within a reasonable amount of time, we divide it into three subproblems: covering, partitioning and layout. Our empirical results demonstrate that our technique produces nearly as good performance as hand-optimized outputs for many kernels
199790
Secure group communication using robust contributory key agreement
Contributory group key agreement protocols generate group keys based on contributions of all group members. Particularly appropriate for relatively small collaborative peer groups, these protocols are resilient to many types of attacks. Unlike most group key distribution protocols, contributory group key agreement protocols offer strong security properties such as key independence and perfect forward secrecy. We present the first robust contributory key agreement protocol resilient to any sequence of group changes. The protocol, based on the Group Diffie-Hellman contributory key agreement, uses the services of a group communication system supporting virtual synchrony semantics. We prove that it provides both virtual synchrony and the security properties of Group Diffie-Hellman, in the presence of any sequence of (potentially cascading) node failures, recoveries, network partitions, and heals. We implemented a secure group communication service, Secure Spread, based on our robust key agreement protocol and Spread group communication system. To illustrate its practicality, we compare the costs of establishing a secure group with the proposed protocol and a protocol based on centralized group key management, adapted to offer equivalent security properties.
15453065
Device-Aware Cache Replacement Algorithm for Heterogeneous Mobile Storage Devices
Hard disks, most prevalent mass-storage devices, have high power consumption and high response time for random I/O requests. Recent remarkable technology improvement of flash memory has made it a rising secondary storage device but flash memory still has high cost per bit. Usage of heterogeneous storage devices such as a pair of a hard disk and a flash memory can provide reasonable cost, relatively acceptable response time, and low-power consumption. In this paper, we propose a novel buffer cache replacement algorithm which targets a mobile computing system with a heterogeneous storage pair of a hard disk and a flash memory. The algorithm partitions the cache per each device and adjusts the size of each partition based on the performance indices of the devices, and manages each partition according to workload patterns. Simulations show that the proposed algorithm yields a hit rate up to two times higher than LRU on the typical mobile traces according to the cache size and achieves also better system I/O response time and energy consumption.
14647313
Energy-efficient disk replacement and file placement techniques for mobile systems with hard disks
Mobile systems have usually used hard disks as the secondary storage devices because of their high capacity per cost and high I/O throughput. However, their high power consumption is the main limiting factor for extending their adoptions in mobile systems. In this paper, we propose enhanced file placement techniques for mobile platforms with multiple smaller disks (instead of a single large disk). We investigate that how many smaller disks are necessary to obtain energy saving while maintaining the required performance using both a simplified energy model and a realistic trace-based simulator under the proposed multiple disk configurations. We also propose energy-efficient file placement techniques, which aggregate files with common attributes the same set of disks. By skewing I/O operations, the proposed techniques achieve additional energy saving. Experimental results show that the proposed techniques can reduce the energy consumption by up to 43% when eight 1" disks are used instead of a single 2.5" disk with an acceptable increase in the average response time.
44579377
Head Detection and Tracking for the Car Occupant's Pose Recognition
This paper describes a Vision-based Occupant Pose Recognition (VOPR) system, which can ensure a safe airbag deployment. Head detection and its tracking are necessary for occupant’s pose recognition in the car, since the position of occupant’s head provides valuable information, such as his pose, size, position, and so on. We use the stereo cameras to extract a disparity map. Against variable lighting conditions including the night drive, we adopt infrared illumination as well as normal one. Results suggest that VOPR system is reliable and performs reasonably well.
7564297
Problem-Independent Schema Synthesis for Genetic Algorithms
As a preprocessing for genetic algorithms, static reordering helps genetic algorithms effectively create and preserve high-quality schemata, and consequently improves the performance of genetic algorithms. In this paper, we propose a static reordering method independent of problem-specific knowledge. One of the novel features of our reordering method is that it is applicable to any problem with no information about the problem. The proposed method constructs a weighted complete graph from the gene distances calculated from solutions with relatively high fitnesses, transforms them into a gene-interaction graph, and finds a gene rearrangement. Extensive experimental results showed significant improvement for a number of applications.