1,720,967 research outputs found
Privacy and Big Data: Scalable Approaches to Sanitize Large Transactional Databases for Sharing
No full textFull text access from Treasures at UT Dallas is restricted to current UTD affiliates.Scalability and privacy form two critical dimensions that will eventually determine the extent of the success of big data analytics. We present scalable approaches to address privacy concerns when sharing transactional databases. Although the benefits of sharing are well documented and the number of firms sharing transactional data has increased over the years, the rate at which this number has grown is not quite what it could have been. Concerns about revealing proprietary information have prevented some retailers from sharing, despite the obvious advantages in an increasingly networked economy. In the context of sharing transactional data, sensitive information is typically based on relationships derived from frequently occurring itemsets, result of surprisingly successful promotions by the retailer, or unexpected relationships identified by the retailer while mining the data. Prior work in this area includes optimal approaches based on integer programming to maximize the accuracy of shared databases, while hiding all sensitive itemsets. While these approaches were shown to solve problems involving up to 10 million transactions, many transactional databases in the big data context are considerably larger and the existing integer programming-based procedures do not scale well enough to solve these larger problems. Consequently, there is no effective solution procedure for such databases in extant literature.
In this paper, we first present an optimal procedure leveraging intuition from linear programming based column generation. Next, we identify a common structure that exists in these problems, and show how it can be taken advantage of through an approach based on sorting and column generation to make the process more efficient. We then illustrate how this structure can be incorporated into the column generation based procedure to develop an effective, scalable heuristic. Computational experiments are conducted on databases with 50 million and 100 million transactions, involving problems that could not be solved using existing optimal procedures. These experiments show that the optimal column generation based procedure can solve problem instances significantly larger than those tackled previously, and that the scalable heuristic identifies nearoptimal solutions quickly in all instances where the optimal solution is known. We investigate the impact of hiding sensitive itemsets on the quality of a rule-based recommender system derived from the shared data. As expected, recommendation quality decreases as the number of sensitive itemsets increases; however, recommendation accuracy stays above 80% of the original rate when using the unmodified data even when there are 1,000 sensitive itemsets to hide. The effect on recommendation accuracy from using the heuristic relative to the optimal approach was very small: the accuracies with the heuristic were over 97% of the corresponding accuracies with the optimal approach in every experiment, and over 99% in the vast majority.Naveen Jindal School of Managemen
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
Essays on Commercialization of Information Technology Products
No full textThis dissertation addresses two important issues in software demonstrations — (i) the design of a feature-limited software demonstration, and (ii) the role of data demonstration when firms bargain over proprietary data. These aspects of software demonstrations are presented in three separate essays provided in chapters 2, 3, and 4 with an introduction in chapter 1.
In the first essay we focus on feature-limited demonstration versions where some of the features are provided free of charge while the remaining features are charged by the vendor. As the specific features included in the feature-limited version influence whether the full product is purchased or not, it is essential that the features included in the feature-limited version be selected judiciously. This study fills the gap in the literature by providing an objective approach to the design of demonstration software.
The second essay investigates the data monetization issue through a negotiation process between a seller and a buyer and also considers the role of a data demonstration by the seller to mitigate the buyer side uncertainty in valuation. Both data sellers and buyers are often unclear about the true potential of the proprietary data, which in turn affects their pricing decision. This raises a fundamental question — how should the price of a unique and proprietary data be decided and is there a way to mitigate the uncertainty in valuation of the data? We model the pricing decision as a Nash bargaining problem where price of the data is mutually decided. The seller has an outside option and will negotiate with the buyer if they expect to gain from the negotiation. The seller also has an option to offer a data demonstration before the negotiation process to reduce the buyer side uncertainty in the valuation. Our results show that the presence of a moderately high outside option can trigger a demonstration. Interestingly, the seller is better off providing a noisy demonstration even when they do not have an outside option but the chances of a high value data is relatively high.
There are several instances where proprietary data can be quite rich and complex and extracting meaningful insights could require considerable effort in such situations. Sometimes the buyer may not always have the ability to effectively analyze the data and is willing to hire a consultant for this task. The consultant acts as a gatekeeper and works with the buyer. Once a decision is made to purchase the data, the buyer pays the seller for the data and the consultant for their services. The prices are arrived at through a negotiation process involving all three parties. The third essay investigates the outcome of the negotiation in the presence of a consultant and observes that proposing a demonstration is not beneficial for the seller in a three-party negotiation. However, it is interesting to find that if the consultant or the seller is aware of the true value while the buyer remains unaware as before, this does not help the consultant or the seller
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
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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