1,720,954 research outputs found
Benfordi seadus
Get PDFKäesolevas bakalaureusetöös antakse ülevaade Benfordi seadusest, mille kohaselt algab
arv numbriga 1 tõenäosusega log 2 0;301, numbriga 2 tõenäosusega log(3=2) 0;176
ja nii monotoonselt kahanevalt kuni tõenäosuseni log(10=9) 0;046, et esimene number
on 9. See seadus kehtib paljudes andmestikes, näiteks rahvaarvude, riikide pindalade,
aktsiaturgude indeksite ja valimistulemuste korral. Antud töös uuritakse ka 2013.
aasta kohaliku omavalitsuse volikogu valimiste tulemuste Benfordi seaduse järgmist
Price Elasticity Based Recommender System
Get PDFSoovitussüsteeme on palju uuritud ja edukalt rakendatud paljudes valdkondades, et suurendada läbimüüki tehes klienditele asjakohaseid soovitusi. Käesoleva magistritöö eesmärgiks on välja töötada uudne soovitussüsteem, mis teeb klientidele personaalseid pakkumisi toote soodushinna huvipakkuvuse põhjal. Seda saab rakendada olukordades, kus soovitusi tehakse allahinnatud toodete seast. Näiteks valides kampaaniatooteid kliendile saadetavasse personaalsesse uudiskirja. Me kaasame tootepõhise kaasfiltreerimise algoritmi täiendusena majanduse valdkonnas kasutatavat nõudluse hinnaelastsust, et võtta arvesse, et tootel on kampaaniaperioodil tavapärasest madalam hind. Hinnates mudeli abil omaelastsuse väärtuse, saame kliendi tootereitingu, mis näitab, kuidas hinna muutumine mõjutab ostetavat kogust. Toodete sarnasuste leidmiseks kasutame ristelastsust, mis liigitab tooted asendus- ja täiendkaupadeks. Selle suuruse leidmine ei nõua tihti esinevat kaugusmõõtude tingimust, et kaks toodet peavad olema ostetud samade klientide poolt. Kirjeldatud soovitussüsteem on rakendatud reaalelulistele supermarketi tehingute andmetele. Süsteemi headuse testimiseks kasutame kahte kampaaniaperioodi, mille allahinnatuid tooteid kasutame võimalike soovitustena. Me saavutame märgatavalt paremad tulemused kasutades ainult kampaaniatoote elastsusi ja mitte asendustoodete vastavaid väärtusi. Kaasates ainult kliendid, kellele leidsime vähemalt 5 pakkumist, saavutame tunduvalt paremad tulemused. Täpsemalt, tehes neile klientidele 12 soovitust (vähem kui 1% kampaaniatoodete arvust), tabame kõik klientide kampaaniatoodete ostud. Parima meetodi korral saavutame kordustäpsuse 0,24, mis on üle 10 korra parem võrreldes meetodiga, mida ettevõte hetkel kasutab, kus soovitused on manuaalselt valitud kliendi segmentide omaduste põhjal. Supermarketi kett on kinnitanud oma soovi, et esitletud meetodit testida, seega antud soovitussüsteemi rakendatakse reaalselt klientidele huvipakkuvate soovituste tegemiseks.Recommender systems have been widely studied and successfully applied in a variety of areas to increase sales by guiding people toward items they are more likely to find interesting. The aim of this thesis is to develop a novel recommender system that suggests items to a client based on the appeal of a product discount. This can be applied to situations where recommendations are made from a list of discounted items such as campaign products selected into personalized sales promotion letters. To take into consideration that the products have cheaper price than usual during the campaign period, we propose an extension to an item based collaborative filtering algorithm, namely the price elasticity of demand known from the field of economics. We represent a client's rating about an item by estimating with a model own elasticity which measures the sensitivity of quantity demanded to the changes in the prices. The similarities of items are computed using cross elasticity which exhibits the substitutional and complementary effects among the products. Unlike traditional similarity metrics, this measure does not assume that the two items have to be purchased by the same clients. The proposed recommender system based on the price elasticity is applied to a real world supermarket transactions dataset. The performance of the system is evaluated on two campaign periods where recommendations are made from the discounted products. The experiments show that it is better to make recommendations based on only campaign product elasticities, without considering the elasticities of campaign products' substitutes. Furthermore, when including only the customers for whom we have found at least 5 recommendations, the performance is considerably better. In particular, when making 10 suggestions (less than 1% of all campaign products), we detect all campaign products that the clients indeed purchased. Using the best method, our approach achieves precision of 0.24, which is over 10 times better in comparison to the method currently used by the company where employees manually select recommendations based on the characteristics of customer segments. The supermarket chain has confirmed their interest in testing the proposed method in practice, hence it will be applied in real world to make more relevant recommendations to the customers
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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