1,721,173 research outputs found
Comment on "Soil salinity assessment by using near-infrared channel and Vegetation Soil Salinity Index derived from Landsat 8 OLI data: a case study in the Tra Vinh Province, Mekong Delta, Vietnam" by Kim-Anh Nguyen, Yuei-An Liou, Ha-Phuong Tran, Phi-Phung Hoang and Thanh-Hung Nguyen
Full text linkNguyen et al. (Prog Earth Planet Sci 7:1, 2020. ) suggest that Landsat 8 OLI can be used to map and monitor soil salinity in the coastal zone of the Mekong River Delta. The authors use empirical correlations between the near-infrared (NIR) band, or vegetation indexes containing the NIR band, and soil salinity. We show that within the coastal portion of the Mekong Delta, extensively ponded due to widespread shrimp farming, about 90% of Landsat 8 pixels are fully or partially covered by water. We then find that, due to strong NIR radiation absorption, NIR reflectance from ponded pixels decreases linearly with increasing water percentage cover, while no significant correlation is found between reflectance and soil salinity. Through detailed new analyses, we conclude that NIR reflectance attenuation cannot be ascribed to vegetation stress caused by soil salinity, but rather to the presence of water ponds. We also show that a similar behavior exists in ponded freshwater inland areas, confirming that the NIR absorption exerted by water is independent of salinity
Catastrophic Failure in Highly Scaled Commercial NAND Flash Memories
No full textHeavy ion single-event measurements on a variety of high density commercial NAND flash memories are reported. Three single event effect (SEE) phenomena were investigated: single effect upsets (SEUs), single effect functional interrupts (SEFIs), and a new high current phenomenon which at high LETs results in catastrophic loss of ability to erase and program the device
Destructive events in NAND Flash memories irradiated with heavy ions
No full textBesides being widely used in virtually all terrestrial applications requiring non-volatile storage, Flash memories are arousing increasing interest with regards to space applications. This work presents new original data on the occurrence of destructive events and supply current spikes in NAND Flash memories exposed to heavy ions. Interestingly enough, these phenomena occur irradiating the devices even in stand-by mode. We examined the dependence of these effects on Linear Energy Transfer (LET) and flux of impinging ions, we used different test protocols, and shielded different blocks of the memory. Our analysis shows that the permanent loss of functionality occurs only with high-LET ions and usually with high particle flux, originating from damage to the charge pumps, likely due to Single Event Gate Rupture. We also show that there is not necessarily a correlation between irreversible damage and supply current spikes, as previously believed, even though they both originate in the charge pump circuitry
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
Resiliency or Sustainability: Disaster Risk Reduction and Airport Development in the Ogasawara Islands
No full textThis paper explores the key concepts behind resilience and sustainability, to identify areas where these concepts conflict and areas of commonality. Then, it examines how key stakeholders in the Ogasawara Islands, Japan, view local hazard vulnerabilities, and how the island could best address them within the context of the development of an airport. Through a series of semi-structured interviews with stakeholders, the authors identified that respondents were divided between maintaining environmental sustainability ver-sus strengthening operational resiliency. Based on these results, an alternative approach to solve the controversy over the development of the airport, which could meet the demands of dif ferent groups within the islands, is proposed.Full Tex
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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