Balancing soft error coverage with lifetime reliability in redundantly multithreaded processors

Silicon reliability is a key challenge facing the microprocessor industry. Processors need to be designed such that they are resilient against both soft errors and lifetime reliability phenomena. However, techniques developed to address one class of reliability problems may impact other aspects of silicon reliability. In this paper, we show that Redundant Multi-Threading (RMT), which provides soft error protection, exacerbates lifetime reliability. We then explore two different architectural approaches to tackle this problem, namely, Dynamic Voltage Scaling (DVS) and partial RMT. We show that each approach has certain strengths and weaknesses with respect to performance, soft error coverage, and lifetime reliability. We then propose and evaluate a hybrid approach that combines DVS and partial RMT. We show that this approach provides better improvement in lifetime reliability than DVS or partial RMT alone, buys back a significant amount of performance that is lost due to DVS, and provides nearly complete soft error coverage. I

Cross-species amplification of eucalyptus SSR markers in Casuarinaceae

Cross-species amplification of Simple Sequence Repeats (SSRs) loci is considered as a cost-effective approach for developing microsatellite markers for new species.We examined the transferability of eucalyptus SSR loci to the economically important members of the Casuarinaceae family. Ten primer pairs targeting (GA)n, (CTT)n, (TGA)n and (GAA)n motifs were screened in Allocasuarina littoralis, A. luehmannii, Casuarina glauca and C. equisetifolia. Up to 30% of the eucalyptus primer pairs amplified SSRs within Casuarinaceae. Nevertheless, in Allocasuarina no amplification products were observed. In Casuarina species, all the locus specific products were monomorphic while few nonspecific bands also amplified

Problem solving processes in the development of three dimensional printing

Thesis (M.S.)--Massachusetts Institute of Technology, Sloan School of Management, 1994, and Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Materials Science & Engineering, 1994.Includes bibliographical references (leaves 88-89).by Gurumurthi Ravishankar.M.S

Guidelines for the design of flexibility in queueing systems : model, measures, and analysis

Thesis (S.M.)--Massachusetts Institute of Technology, Sloan School of Management, 2004."September 2004."Includes bibliographical references (leaves 63-64).(cont.) have a relatively limited impact on throughput and overall utilization measures when compared to strategic flexibility design parameters such as the assignment of long-term job responsibilities to servers. However, we show that this influence on performance is significant enough that various flexibility design alternatives are better compared after taking into account the control policy that will be used to operate the system. Furthermore, and motivated by the recent interest in revenue management techniques for operational systems, we show that such operational control policies can have disproportionate influence on revenue and cost measures of performance; this fact further underscores the importance of having such models, measures, and analytical tools to examine various system design alternatives for improving performance.An analytical and computational framework is presented that has been developed for the performance analysis of arbitrary queueing networks with multiple heterogeneous servers and multiple customer classes, where customers have the flexibility of being processed by more than one server and servers possess the capability of processing more than one customer class. Jobs of a given class may arrive according to an independent Poisson process to a facility consisting of multiple heterogeneous servers. The service time for the processing of any given job class at any given server is assumed to be exponentially distributed with a mean that could vary by job class as well by server. Significantly, we do not impose any restriction on the set of job classes that can be processed by any given server. Assuming finite work-in-process capacity in terms of the number of jobs already in the system, we allow for multiple stages of processing in the queueing system. In order to motivate the research, we first identify the different forms of flexibility in such queueing systems that are relevant to managers given their importance as design factors and control policies for higher performance. Next, we present an analytical framework whose goal is to capture for performance analysis, the relative impact of the different forms of flexibility so identified. Third, we demonstrate the usefulness of the modeling framework through a simple but illuminative numerical analysis of single-stage queuing systems that in turn shows the significance of these flexibility mechanisms to the performance measures of interest to system managers. In terms of insights from the modeling efforts, we first show that when evaluated within this framework, control policies such as job-routing and job-selection rulesby Suryanarayanan Gurumurthi.S.M

Purification of antifungal protein against blister bark pathogen of Casuarina equisetifolia J. R. Forster et G. Forster

Aprotein extract from the leaves of Andrographis paniculata (Acanthaceae) was found to inhibit the spore germination and hyphal extension of Trichosporium vesiculosum, the blister bark pathogen of Casuarina equisetifolia. The antifungal protein component was further purified from the crude extract and the molecular mass of the toxic protein was estimated to be 39.5 kDa

Purification of antifungal protein against blister bark pathogen of Casuarina equisetifolia J. R. Forster et G. Forster

Aprotein extract from the leaves of Andrographis paniculata (Acanthaceae) was found to inhibit the spore germination and hyphal extension of Trichosporium vesiculosum, the blister bark pathogen of Casuarina equisetifolia. The antifungal protein component was further purified from the crude extract and the molecular mass of the toxic protein was estimated to be 39.5 kDa

An Estimator for the Sensitivity to Perturbations of Deep Neural Networks

For Deep Neural Networks (DNNs) to become useful in safety-critical applications, such as self-driving cars and disease diagnosis, they must be stable to perturbations in input and model parameters. Characterizing the sensitivity of a DNN to perturbations is necessary to determine minimal bit-width precision that may be used to safely represent the network. However, no general result exists that is capable of predicting the sensitivity of a given DNN to round-off error, noise, or other perturbations in input. This paper derives an estimator that can predict such quantities. The estimator is derived via inequalities and matrix norms, and the resulting quantity is roughly analogous to a condition number for the entire neural network. An approximation of the estimator is tested on two Convolutional Neural Networks, AlexNet and VGG-19, using the ImageNet dataset. For each of these networks, the tightness of the estimator is explored via random perturbations and adversarial attacks.Comment: Actual work and paper concluded in January 201