1,720,967 research outputs found
A Comparison of Methods for Forecasting Demand for Slow Moving Car Parts
Get PDFThis paper has a focus on non-stationary time series formed from small non-negative integer values which may contain many zeros and may be over-dispersed. It describes a study undertaken to compare various suitable adaptations of the simple exponential smoothing method of forecasting on a database of demand series for slow moving car parts. The methods considered include simple exponential smoothing with Poisson measurements, a finite sample version of simple exponential smoothing with negative binomial measurements, and the Croston method of forecasting. In the case of the Croston method, a maximum likelihood approach to estimating key quantities, such as the smoothing parameter, is proposed for the first time. The results from the study indicate that the Croston method does not forecast, on average, as well as the other two methods. It is also confirmed that a common fixed smoothing constant across all the car parts works better than maximum likelihood approaches.Count time series; forecasting; exponential smoothing; Poisson distribution; negative binomial distribution; Croston method.
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe 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
Get PDF“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
Get PDFWe 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
Get PDFWe 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
Scotland referendum and NZ election previews
No full textIn the next week there will be a referendum in Scotland to decide whether Scotland should become an independent country; polls currently show a very close race, with NO to independence slightly ahead. A general election will also be held in New Zealand, where the centre right Nationals are likely to win a third term in office.
Scotland Referendum
The Scotland referendum will be held on Thursday 18 September, with polls closing at 10pm UK time (7am Friday Australian Eastern). If the result is clear, it should be known sometime on Friday afternoon Aus time.
The desire of many Scots to become independent seems to be due to antipathy to Margaret Thatcher’s Prime Ministership. Antony Green has a long post about the background to the current referendum, and the Tory vote in Scotland fell dramatically during Thatcher’s years. This trend against the Tories has continued, and they held zero Scotland seats after the 1997 election, and won only one seat at the 2001, 2005 and 2010 elections. In the 2010 election, Scotland’s result meant that the Tories failed to win a majority of UK seats, leading to the current Tory - Lib Dem coalition government. In Scotland, the Tories have fallen to fourth place behind Labour, the Lib Dems and the Scottish Nationalists.
Polling in the lead up to the referendum has clearly favoured the NO side until recently. The largest shifts have come from polls that previously leaned towards NO. A YouGov poll in early August put NO ahead by 61-39, but there were four-point shifts towards YES in each of the next three YouGov polls to put the YES side ahead 51-49 in a poll conducted in early September - the first YES lead any poll had shown. Last Friday’s YouGov had NO back in front by a narrow 52-48 margin.
On the other hand, two polls that have always seen a much closer race than YouGov were unchanged recently; both Survation and Panelbase were showing NO leads of 53-47 and 52-48 respectively. It appears that the referendum was always closer than YouGov and other polls stated, but now the polls that previously leaned towards NO have corrected; these polls have seen dramatic swings, while polls which were YES-favourable have seen none or little change.
Overnight, four polls have been released. Three of them have NO leading by between 54-46 and 51-49, but one has YES leading by 54-46. That big YES poll used a sample of only 700, and is likely to be an outlier. A good rule to follow with polls is that if one poll has a major disagreement with the other polls, that poll is far more likely to be wrong than the others. The Poll Bludger is now using BludgerTrack to follow the Scottish referendum polls, and currently has NO ahead by 51.4-48.6.
The NO campaign is still marginally ahead, and is more likely to prevail next Thursday, but this contest has become much closer than could have been predicted even two weeks ago.
If Scotland becomes an independent country, it would hurt Labour’s chances of winning UK general elections. As noted before, without Scotland, the Tories would have won a majority of seats in their own right at the 2010 UK election.
For more information on Scotland’s referendum, I recommend UK Polling Report.
New Zealand Election
The New Zealand election will be held on Saturday 20 September, with polls closing at 7pm NZ time (5pm Aus eastern). Preliminary results will be published through Saturday night.
If NZ used a single member system, the result would already be effectively known, as the centre right Nationals have been in at least the mid-40’s in all recent polls, while Labour has been below 30%. In a single member system, this would result in a crushing National win.
However, NZ uses mixed member proportional (MMP) representation. Under MMP, a party must either win a single member electorate, or win at least 5% of the overall vote, to qualify for a proportional allocation of parliamentary seats. Electors are given two votes, one for their electorate and one for their party. It is the party vote, not the electorate vote, that decides how seats will be distributed.
The NZ parliament has 120 seats awarded by proportional representation based on the party vote. Parties that win a large proportion of single member seats are penalised by not getting many party list seats. A peculiarity of the system is the “overhang”; this occurs when a party wins more single member seats than it deserves based on its party vote. In such a case, the party is allowed to keep its extra seats, and the size of Parliament is expanded. Owing to this, the Parliament following the 2011 election had 121 seats.
The Curiablog NZ poll aggregate currently has National on 48.6%, Labour on 25.6%, the Greens on 12.8%, NZ First on 5.8% and the Conservatives on 3.5%. A Parliament of 123 is anticipated, with the assumption that the Maori and Manu parties will win more seats than they deserve proportionally. National is apparently giving its allies ACT and United Future free conservative single member electorates.
The centre right coalition is National, United Future and ACT. The center left is Labour, the Greens and Mana. National could be hurt if the Conservatives fail to reach 5%, as these right wing votes would then be wasted. The current projection is that the centre right coalition will just have a bare majority, with 62 of 123 seats, well ahead of the centre left’s 51. It would only take a one seat switch for the centre right to lose majority status, so it is closer than it looks. Nevertheless, John Key is likely to be re-elected to a third term as New Zealand’s Prime Minister.
Adrian Beaumont does not work for, consult to, own shares in or receive funding from any company or organisation that would benefit from this article, and has no relevant affiliations.
This article was originally published on The Conversation. Read the original article.
Image: ballot / Shutterstoc
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
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
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