1,720,955 research outputs found
Studies on Ordinal Ranking with Regression
No full text排序問題的相關研究在近年來漸趨熱門，在網路搜尋引擎、推薦系統等許多方面都有著廣泛的應用。而隨著網路的資訊量爆炸，如何藉由這些大量資料來快速地訓練出一個好的排序系統，便成為日益重要的問題。本篇論文著重於處理龐大的序數資料集，不同於傳統分類問題中的類別，在序數資料集內的類別之間帶有等級差距的資訊。本論文中研究如何於序數資料集上，利用迴歸分析去處理兩種類型的排序相關問題。其中一種排序問題是對資料做評等，排序系統會判斷此資料是屬於哪種序數等級；另外一種排序問題則是頂端排序問題，旨在研究如何讓與搜尋關鍵字相關的資料文件，能依其相關性高低排序產生一個搜尋列表。我們提出一個架構可以和各式迴歸相關演算法結合來處理排序問題，在此架構中導入了成本觀念去處理等級差距的資訊，而在兩個問題上的實驗結果都顯示了此架構可以有效提升排序結果。我們也針對在頂端排序問題上的一個熱門評量標準，進而提出了一個有效的成本函數，實驗結果則顯示此成本函數在此評量標準上更可有效提升排序效果。Ranking is a popular research problem in recent years and has been used in wide range of applications including
web-search engines and recommendation systems.
In this thesis, we study on two ranking problems, the ordinal ranking problem and the top-rank problem.
We propose a novel ranking approach, cost-sensitive ordinal classification via regression (COCR), which respects the discrete nature of the ordinal ranks in real-world data sets. In particular, COCR applies a theoretically-sound reduction from ordinal to binary classification
and solves the binary classification sub-tasks with point-wise regression. Furthermore, COCR allows specifying mis-ranking costs to further boost the ranking performance.
We conduct experiments on two ranking problems respectively.
On the ordinal ranking problem, we compare different approaches based on decision trees.
The results show that the proposed COCR can perform better on many data sets when coupled with the appropriate cost.
Furthermore, on the top-rank problem, we derive the corresponding cost of a popular ranking criterion, Expected Reciprocal Rank (ERR), and plug the cost into the COCR approach. The resulting ERR-tuned COCR enjoys the benefits of both efficiency by using point-wise regression and top-rank prediction accuracy from the ERR criterion.
Evaluations on two large-scale data sets, including
``Yahoo! Learning to Rank Challenge'' and ``Microsoft Learning to Rank'', verify that some basic COCR settings outperform commonly-used regression approaches significantly. In addition, even better performance can often be achieved by the ERR-tuned COCR
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
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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