7962101
A New Hybrid Solution to Boost SAT Solver Performance
Due to the widespread demands for efficient SAT solvers in Electronic Design Automation applications, methods to boost the performance of the SAT solver are highly desired. We propose a Hybrid Solution to boost SAT solver performance in this paper, via an integration of local and DPLL-based search approaches. A local search is used to identify a subset of clauses to be passed to a DPLL SAT solver through an incremental interface. In addition, the solution obtained by the DPLL solver on the subset of clauses is fed back to the local search solver to jump over any locally optimal points. The proposed solution is highly portable to the existing SAT solvers. For satisfiable instances, up to an order of magnitude speedup can be obtained via the proposed hybrid solver.
22689188
Bilateral Testing of Nano-scale Fault-Tolerant Circuits
As the technology enters the nano dimension, the inherent unreliability of nanoelectronics is making fault-tolerant architectures increasingly necessary in building nano systems. Because fault-tolerant hardwares help to mask the effects caused by increased levels of defects, testing the functionality of the chip together with the embedded fault-tolerance becomes a tremendous challenge. In this paper, a new bilateral testing framework for nano circuits is proposed, where multiple stuck-at faults across different modules in a triple module redundancy (TMR) architecture are considered. In addition, a new test generator is presented for the bilateral testing that takes into account the enormous number of bilateral stuck-at faults possible with new types of guidance in the search, and it can generate a set of vectors that can test the TMR-based nano circuit as a single entity. Experimental results reported for ISCAS’85 and ITC99 circuits demonstrate that the bilateral testing can help to capture many more defects which the single stuck-at fault misses.
3191506
A Fast Approximation Algorithm for MIN-ONE SAT
In this paper, we propose a novel approximation algorithm (RelaxSAT) for MIN-ONE SAT. RelaxSAT generates a set of constraints from the objective function to guide the search. The constraints are gradually relaxed to eliminate the conflicts with the original Boolean SAT formula until a solution is found. The experiments demonstrate that RelaxSAT is able to handle very large instances which cannot be solved by existing MIN-ONE algorithms; furthermore, very tight bounds on the solution were obtained with one to two orders of magnitude speedup.
13050911
Efficiency Centric Communication Model for Wireless Sensor Networks
Recent studies on radio reality provided strong evidence that radio links between low-power sensor devices are extremely unreliable. In this paper, we study how to improve energy efficiency for reliable communication using such unreliable links. We identify an optimal bound on energy efficiency for reliable communication, and propose a new communication model in the link layer that asymptotically approaches this bound. This new model indicates a better path metric compared to previous path metrics, and we validate this by establishing a routing infrastructure based on this metric, which indeed achieves a higher energy efficiency compared to other stateof-the-art approaches. We present results from a systematic analysis, simulations and prototype experiments based on the MicaZ platform. The results give us fundamental insights on communication efficiency over unreliable links.
393655
A Novel Artificial Immune System for Multiobjective Optimization Problems
This study presents a novel weight-based multiobjective artificial immune system (WBMOAIS) based on opt-aiNET. The proposed algorithm follows the elementary structure of opt-aiNET, but has the following distinct characteristics: At first,a randomly weighted sum of multiple objectives is used as a fitness function; Secondly, the individuals of the population are chosen from the memory, which is a set of elite solutions. Lastly, in addition to the clonal suppression algorithm similar to that used in opt-aiNET, a new truncation algorithm with similar individuals (TASI) is presented in order to eliminate the similar individuals in memory and obtain a well-distributed spread of non-dominated solutions. Simulation results show WBMOAIS outperforms the vector immune algorithm (VIS) and the elitist non-dominated sorting genetic system (NSGA-II).
17563993
The e-logistics framework in e-commerce
The growth of the supply chain concept has required logistics organizations to improve the flow of information both internally and externally. The increased information requirements have facilitated an integration of logistics information systems (LIS) and supply chain information systems in many companies. The increasing use of electronic commerce and other LIS tools and techniques will shape the business process for the foreseeable future. This paper introduces such a framework for e-logistics processes integration based on Web Services via incorporating (1)common alliance layer (2) adaptation layer; and (3) dynamic data binding mechanism. This framework can be adopted as a new service delivery model which uses a design pattern and solution templates. Companies should understand their options and their impacts when making decisions to support their supply chain systems.
1319991
Context-aware wireless sensor networks for assisted living and residential monitoring
Improving the quality of healthcare and the prospects of "aging in place" using wireless sensor technology requires solving difficult problems in scale, energy management, data access, security, and privacy. We present AlarmNet, a novel system for assisted living and residential monitoring that uses a two-way flow of data and analysis between the front- and back-ends to enable context-aware protocols that are tailored to residents' individual patterns of living. AlarmNet integrates environmental, physiological, and activity sensors in a scalable heterogeneous architecture. The SenQ query protocol provides real-time access to data and lightweight in-network processing. Circadian activity rhythm analysis learns resident activity patterns and feeds them back into the network to aid context-aware power management and dynamic privacy policies.
19803744
Effects of Similarity-Based Selection on WBMOIA: A Weight-Based Multiobjective Immune Algorithm
With a comparison to the random selection approach used in the weight-based multiobjective immune algorithm (WBMOIA), this paper proposes a new selection approach based on the truncation algorithm with similar individuals (TASI). Then the effect of the proposed selection approach is examined on the performance of WBMOIA. On one hand, the performance is compared between WBMOIA with the random selection approach and WBMOIA with the proposed selection approach. On the other hand, simulation results on a number of problems are presented to investigate if there exists any value of the reduction rate where WBMOIA performs well. Experiment results show that the performance of WBMOIA can be improved by the proposed selection approach and a better reduction rate can be obtained for each test problem.