1,720,971 research outputs found
DRAM Reliability: Aging Analysis and Reliability Prediction Model
No full textAn increasing amount of critical applications use DRAM as main memory in its computing systems. It it therefore extremely important that these memories function correctly during their lifetime in order to prevent catastrophic failures. Already during the design phase, the reliability of the circuit needs to be predicted so that a reasonable lifetime expectation can be given. Although the importance of reliability analysis is clear, in literature not much research on DRAM reliability is available to designers. This thesis proposes a two phasedDRAM reliability prediction model that can be used in the circuit design phase. During the first phase, the circuit performance is analyzed for different wear-out mechanisms affecting different subcomponents in the design. In the second phase, the results of the first phase are then used to determine the reliability of the circuit.In the first phase, the wear-out effects of Bias Temperature Instability (BTI) Hot Carrier Injection (HCI) and radiation trapping as well as transistor mismatch are examined. BTI is modeled using the RD-model, HCI with the lucky electron model, transistor mismatch with Pelgrom’s model. Wear-out caused by radiationtrapping is modeled as Gate Induced Drain Leakage (GIDL), the data for which are derived from retention time degradation measurements of an irradiated commercial DRAM. The circuit performance is analyzed per subcomponent of the DRAM design in a range of different metrics. Furthermore, the aging effects on adwonscaled version of the circuit are investigated.In the second phase, reliability functions are derived from the results from phase one per wear-out mechanism and per subcomponent. These reliability functions are used in an analytical reliability model which yields the overall circuit reliability.The results from the first phase show degradation of the retention time as well as degradation of sensing delay metrics. Due to the relative low duty factor of memory cells, BTI and HCI have minor impact on the memory cell circuit performance. Radiation however, renders the circuit useless once the Total Ionizing Dose (TID) becomes more than 126 krad. On other subcomponents than the memory cells, BTI and HCI shift the reference voltage which results in an increase of retention time. BTI and HCI stressing of the sense amplifieralso slightly increases retention time but mainly increases sensing delay. For both reference cells and the sense amplifier it holds that higher radiation doses break down the circuit completely. The same effects hold for the downscaled circuit, although the observed effects are more severe than in the unscaled device.The system reliability prediction in the second phase shows the importance of individual reliability prediction of the subcircuits and wear-out mechanisms. Via the individual analysis, it becomes clear that the system reliability is mostly impacted by the degradation of the sense amplifier delay due to BTI and HCI. Other metric variations, like the increase in retention time caused by the reference cells, have less impact. It was found that the system reliability decreases to 0.84 after 1·108s at a stressing temperature of 300K. <br/
Device-Aware Test for Threshold Voltage Shifting in FeFET
Full text linkFerroelectric Field-Effect Transistors (FeFETs) are promising candidates for non-volatile memory (NVM) technologies, especially in embedded systems and edge computing. However, due to their physical characteristics, FeFETs exhibit unique defects—such as Threshold Voltage Shifting (TVS) caused by trap charges in the oxide layer—that are not captured by conventional defect models. This study adopts the Device-Aware Test (DAT) methodology to model these defects by incorporating their impact into the electrical parameters, calibrated using measurement data. Defect injection, circuit-level simulations, and fault analysis are performed to derive realistic fault models. Finally, the March algorithm and Design-for-Test (DfT) techniques are proposed to effectively detect these defects
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
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