748684
Detection probabilities of interconnect breaks: an analysis
An interconnect break is a break that occurs in the interconnect wiring, resulting in logic gate inputs being disconnected from the drivers and causing the wire to float. Interconnect breaks are the most common types of breaks in modern CMOS integrated circuits, so testing and detecting these breaks has become very important. This paper proposes a model by which standard tests for stuck-at-faults can be used to detect interconnect breaks in a circuit. This paper presents a worst-case analysis of the detection of these breaks and calculate the minimum number of test vectors required to detect breaks with a specified confidence level, using n-detection principles. To enhance the understanding of the breaks in the circuit, we present a statistical model based on the length distribution of the wires surrounding the floating wire where the break occurs. From the model we compute the detection probabilities of such breaks and show that the worst case of detection is when the bias voltage is the same as the logic threshold voltage.
11538916
Reducing power consumption in memory ECC checkers
A method is proposed for reducing power consumption in memory ECC checker circuitry that provides SEC-DED. The degrees of freedom in selecting the parity check matrix are used to minimize power with little or no impact on area and delay. The power minimization method is applied to two popular SEC-DED codes: standard Hamming codes and odd-column-weight Hsiao codes. Experiments on actual memory traces of Spec and MediaBench benchmarks indicate that considering power in addition to area and delay when selecting the parity check matrix can result in power reductions of up to 27% for Hsiao codes and up to 41% for Hamming codes.
29763170
Fractal image compression: a randomized approach
The fractal image compression is inherently time intensive and thus there is a growing need to increase its speedup. This paper presents a fast encoding scheme where the domain blocks are searched randomly for every range block. An analysis of the basic fractal image compression method has been carried out and on the basis of the analysis a method for image characterization has been proposed. Then a detailed theoretical analysis of this randomized fractal compression scheme has been presented and the results are validated with the experimental ones. The random approach has been found to be quite efficient giving considerable increase in speed-up compared to several other approaches.
14429447
iSimBioSys: a discrete event simulation platform for 'in silico' study of biological systems
With the availability of huge databases cataloguing the various molecular "parts" of complex biological systems, researchers from multiple disciplines have focused on developing modeling and simulation tools for studying the variability of cellular behavior at a system level - encompassing the dynamics arising from many species of interacting molecules. In this work, we present a system engineering approach to model biological processes. In this approach, a biological process is modeled as a collection of interacting functions driven in time by a set of discrete events. We focus on the discrete event simulation platform, called "iSimBioSys", which we have developed for studying the dynamics of cellular processes in silico. As a test-bed for studying our approach we model the two component PhoPQ system, responsible for the expression of several virulence genes in Salmonella Typhimurium. We analyzed the effect of extra cellular magnesium on the behavioral dynamics of this pathway using our framework and compared the results with an experimental system. We also analyze the performance of iSimBioSys, based on the model biological system, in terms of system usage and response.
1980879
Quantitative Quality Control in Microarray Experiments and the Application in Data Filtering, Normalization and False Positive Rate Prediction
Data preprocessing including proper normalization and adequate quality control before complex data mining is crucial for studies using the cDNA microarray technology. We have developed a simple procedure that integrates data filtering and normalization with quantitative quality control of microarray experiments. Previously we have shown that data variability in a microarray experiment can be very well captured by a quality score q(com) that is defined for every spot, and the ratio distribution depends on q(com). Utilizing this knowledge, our data-filtering scheme allows the investigator to decide on the filtering stringency according to desired data variability, and our normalization procedure corrects the q(com)-dependent dye biases in terms of both the location and the spread of the ratio distribution. In addition, we propose a statistical model for false positive rate determination based on the design and the quality of a microarray experiment. The model predicts that a lower limit of 0.5 for the replicate concordance rate is needed in order to be certain of true positives. Our work demonstrates the importance and advantages of having a quantitative quality control scheme for microarrays.
1421735
Scalable Self-Stabilization
This paper presents a methodology for a synchronous non-reactive distributed system on a tree topology to stabilize from a k-faulty configuration in a time independent of the size n of the system. In the proposed methodology, processes first measure and compare the sizes of the faulty regions, and then use this information to schedule actions in such a way that the size of the faulty regions progressively shrink, until they completely disappear. We demonstrate that when k processes fail, the stabilization time is O(k2). Apart from its applicability to a wide class of problems, the proposed method achieves scalability with a low space complexity of O(�.(�.k+log2n)) per process, where � is the maximum degree of a node.
33976120
Concurrent Reading and Writing with Mobile Agents
This paper presents a method using which a set of reading and writing agents concurrently read and update the global state of the network. In addition to the consistency of the snapshot and the reset states, our protocol preserves the atomicity of the reads and writes, despite the fact these operations are non-blocking. Potential applications include the design of multi-agent protocols for self-stabilization, self-healing and adaptation.