Fault tolerance in super-scalar and VLIW processors

In this paper, we present a method for utilizing the spare capacity in super-scalar and very long instruction word (VLIW) processors to tolerate functional unit failures. Unlike previous work that was primarily interested in detection of transient faults, we are concerned with more permanent and/or intermittent faults which necessitate processor reconfiguration. Our method utilizes the VLIW compiler or the superscalar scheduler to insert redundant operations whenever idle functional units exist. The results of these redundant operations are used to detect and diagnose functional unit failures. For super-scalar processors, the scheduler can then utilize this information to ensure that operations are performed only on non-faulty units. In VLIW processors, this is equivalent to recompiling the code to run on the remaining non-faulty functional units. Since in certain applications, recompilation may not be possible, we consider two alternative reconfiguration strategies for VLIW processors. These strategies sacrifice storage space and execution time, respectively, in order to reconfigure without recompiling. We present Markov models that describe the behavior of processors using these different approaches and we evaluate their reliabilities. The results show that, while super-scalar and VLIW with recompilation provide the highest reliability, all proposed strategies significantly increase reliability over that of an unprotected processor

Performance analysis of a generalized upset detection procedure

A general procedure for upset detection in complex systems, called the data block capture and analysis upset monitoring process is described and analyzed. The process consists of repeatedly recording a fixed amount of data from a set of predetermined observation lines of the system being monitored (i.e., capturing a block of data), and then analyzing the captured block in an attempt to determine whether the system is functioning correctly. The algorithm which analyzes the data blocks can be characterized in terms of the amount of time it requires to examine a given length data block to ascertain the existence of features/conditions that have been predetermined to characterize the upset-free behavior of the system. The performance of linear, quadratic, and logarithmic data analysis algorithms is rigorously characterized in terms of three performance measures: (1) the probability of correctly detecting an upset; (2) the expected number of false alarms; and (3) the expected latency in detecting upsets

Measuring Cerebrospinal Fluid Pressure With a Fluid Manometer

4th Place 2017 Undergraduate Research ForumA fluid manometer is the device of choice when measuring Cerebrospinal Fluid (CSF) pressure. CSF pressure can be an important indicator of certain pathologies of the body. CSF pressure is also relevant because it can be used as a surrogate for intracranial pressure. When measuring CSF pressure, a lumbar puncture is necessary, where a needle is used to gain access into the spinal canal. In theory the pressure reading should be taken after the fluid has stopped rising in the column, and equilibrium pressure is achieved between the spinal canal and the manometer. It has been hypothesized that the amount of time physicians wait to record CSF pressure may not be adequate for certain lumbar puncture needle gauges and types. To test this, a large fluid column was created above a port with a known height. The time to generate a fluid column in the manometer within 0.5 cm of the fluid height was recorded. This test was completed for many needles and a range of fluid column heights. The testing revealed that for certain needles, especially 25 Ga., 27 Ga., and 29 Ga., the time to record an accurate CSF pressure reading is quite long. Waiting more than 30 mins with a lumbar puncture needle inserted is not practical for the physician or patient. The results also showed that the method of measuring CSF pressure with a fluid manometer requires careful adherence to technique and knowledge of needle characteristics. These results are important because many published studies were based on data taken using fluid manometers, which may affect conclusions drawn from previous studies.The Ohio State University College of EngineeringNo embargoAcademic Major: Biomedical Engineerin

Experimentally Investigating the Joint Effects of Physical Activity and Sedentary Behavior on Depression: A Randomized Controlled Trial

Objective: To experimentally examine whether increasing sedentary behavior, among a young adult active population, for one week is still associated with increased depression symptomology even when allowing for a moderate engagement in physical activity (PA). Methods: Participants were confirmed as active via self-report and accelerometry during baseline and randomly assigned to one of three experimental groups. The Sedentary Intervention Group (n=19) reduced steps to less than 5000/day and were not alloto exercise for one-week; the Reduced MVPA (moderate-to-vigorous PA) Group (n=18) reduced steps to less than 5000/day but exercised for 50% of their previously reported vigorous PA for one-week; and the Control Group (n=20) maintained normal activity for one-week. PA and depression levels were assessed at baseline, postintervention, and after one week of resumed normal activity for the intervention groups. Results: The experiment was successful in altering physical activity levels among the intervention groups and maintaining activity habits in the control group (FInteraction =16.053, P \u3c 0.001, ?2p¬ = 0.391). Depression symptomology remained constant across the two time periods in the control group. For both intervention groups (Sedentary Group and Reduced MVPA Group), depression statistically significantly increased during the inactive week and then resumed back to baseline levels after a week of resumed activity. However, there were no differential trends in depression (FInteraction = 0.276, P = 0.760, ?2p¬ = 0.008) among these two intervention groups. Conclusion: We provide experimental evidence that increasing sedentary behavior causes an increase in depression symptomology among young active adults. We did not, however, observe a joint effect of sedentary behavior and exercise on changes in depression

Character Standardization: Japan\u27s Influence on China

Due to the pictographic nature of Chinese characters in Japan (Kanji) and China (Hanzi), throughout history the use of these characters has been inconsistent. In the mid-1900s the governments of both countries decided to regulate their use in order to make reading and writing both easier and more consistent. Both of the governments have officially done this multiple times through a process of both simplification and standardization. Simplification is to reduce the complexity of the characters, and standardization is to produce a set list of characters that can be used by the government and education system. The most recent updates to these lists in both countries are the List of Chinese Characters for General Use in Japan (2010) and the General Purpose Normalized Chinese Character List in China (2013). Using these two lists as evidence, I will show how Japan has been influencing Chinese language policies in the standardization of characters through technology, tourism, and food culture. I also introduce the history of Chinese characters in Japan and China’s influence on Japan throughout the centuries to clarify the importance and the originality of my argument. Furthermore, I detail the process of simplification and standardization through the history of character lists in both countries

Efficient diagnosis of multiprocessor systems under probabilistic models

The problem of fault diagnosis in multiprocessor systems is considered under a probabilistic fault model. The focus is on minimizing the number of tests that must be conducted in order to correctly diagnose the state of every processor in the system with high probability. A diagnosis algorithm that can correctly diagnose the state of every processor with probability approaching one in a class of systems performing slightly greater than a linear number of tests is presented. A nearly matching lower bound on the number of tests required to achieve correct diagnosis in arbitrary systems is also proven. Lower and upper bounds on the number of tests required for regular systems are also presented. A class of regular systems which includes hypercubes is shown to be correctly diagnosable with high probability. In all cases, the number of tests required under this probabilistic model is shown to be significantly less than under a bounded-size fault set model. Because the number of tests that must be conducted is a measure of the diagnosis overhead, these results represent a dramatic improvement in the performance of system-level diagnosis techniques

Role of Accounting in the Taxing Process, An Address before the National Tax Association, June 6, 1946

https://egrove.olemiss.edu/aicpa_guides/2317/thumbnail.jp