1,720,994 research outputs found
Current tracking technique enabling 1-bit/cell storage in Ge-rich phase change memory
No full textThis brief presents a system architecture designed to enable 1-bit-per-cell storage in Ge-rich phase change memory (PCM) even in the presence of the resistance drift of the low-resistance (SET) state, thus overcoming the intrinsic low storage density (half bit per cell) of the currently used differential solutions. The read reference current is automatically adjusted to best exploit the reading window between the RESET and the SET state that changes over time. The working principles of the system are presented, discussed, and experimentally validated. The proposed system was implemented exploiting a 110-nm BCD embedded PCM test chip and successfully tested in the temperature range from -40 °C to +150 °C
Drift induced rigid current shift in Ge-Rich GST Phase Change Memories in low resistance state
No full textGe-Rich GST based Phase Change Memories (PCMs) represent a valid candidate for embedded non-volatile storage due to high-temperature stability, which enables data retention compatible with automotive applications and data integrity in case of soldering reflow stress. Howeover, Ge-Rich GST based PCMs are affected by resistance drift both for cells programmed in the high-resistance state (HRS) and for cells programmed in the low-resistance state (LRS). Our experimental investigation, carried out on a population of 500k cells in a memory array, showed that the variation over time of the LRS cell current is substantially constant for all the cells in the array, regardless of the value of the cell current (and, hence, of the cell resistance) measured just after programming, which results in a rigid cell current shift. Starting from the obtained experimental results, we derived an expression to calculate the drift coefficient in LRS cells as a function of their initial resistance
Effect of a westward transmeridian flight on ambulatory blood pressure monitoring in normotensive subjects
No full textOBJECTIVE: To evaluate the effects of a westward transmeridian flight over six time zones (from Milan to New York) on ambulatory blood pressure monitoring (ABPM) in normotensive individuals.
METHODS: Eighteen normotensive subjects (blood pressure < 140/90 mmHg), 11 men and seven women, of mean age 38.3 years, were studied. On the day of travel they underwent 26 h noninvasive ABPM (started at 1100 h); the take-off time was 1200 h and the landing time was 8 h later, at 1400 h New York time (2000 h Italian time). Subjects were requested not to sleep until 2300 h and to get up at 0700 h the following morning. The results were compared with those of a 26 h ABPM performed in Italy the week before during which they slept from 2300 h to 0700 h.
RESULTS: During the flight blood pressure and heart rate did not change compared with values during the corresponding time interval of the control day. After the landing, during the New York afternoon and evening (corresponding to the Italian sleeping time), blood pressure and heart rate remained unchanged, whereas during the night they decreased significantly, although their drop was less pronounced than that during the control da
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
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