1,721,052 research outputs found
New methods and strategies towards total synthesis of (9S)-dihydroerythronolide A
No full textDisclosed are studies directed towards the total synthesis of (9S)-dihydroerythronolide A. Towards this goal an advanced intermediate, 14 member bis[allene] macrolactone was synthesized. A general method of cuprate-mediated carbon nucleophile delivery to spirodiepoxides was developed. An unprecedented macrolactonization to form bis[allene] macrolactone and macrocyclic stereocontroled epoxidation of this system was achieved. In a separate study, the highly stereocontroled formation of spirodiepoxides and excellent regiocontroled spirodiepoxide opening was developed. This method relies upon the presence of a silyl substituent on the allene. This finding was applied to the total synthesis of epicitreodiol.Ph.D.Includes bibliographical references
Skyline computation over multiple points and dimensions
No full textSkyline is a technique in database management system for multi-criterion decision making based on dominance analysis. Skyline overcomes the limitation of relational databases by handling the criteria that are inversely proportional to each other. Traditional skyline operation is conceptualized over two dimensions only, and it finds out single interesting point. In this paper we extend the capability of skyline to work with multiple dimensions and to search the multiple interesting points from the given search space. The work furthermore ranks skyline points with respect to the multiple interesting points. However, we restrict the computational complexity within a fixed upper bound. Skyline is commonly applied on tourism industries, and we consider two different case studies from this domain and execute the proposed methodology over the real-life data. Comparative study is given based on different parameters, and statistical analysis is also performed to illustrate the efficacy of the proposed method over the existing methods
Materialized view construction using linearizable nonlinear regression
No full textQuery processing at runtime is an important issue for data-centric applications. A faster query execution is highly required which means searching and returning the appropriate data of database. Different techniques have been proposed over the time and materialized view construction is one of them. The efficiency of a materialized view (MV) is measured based on hit ratio, which indicates the ratio of number of successful search to total numbers of accesses. Literature survey shows that few research works has been carried out to analyze the relationship between the attributes based on nonlinear equations for materialized view creation. However, as nonlinear regression is slower, in this research work they are mapped into linear equations to keep the benefit of both the approaches. This approach is applied to recently executed query set to analyze the attribute affinity and then the materialized view is formed based on the result of attribute affinity
SentiTSMixer: A Specific Model for Sales Forecasting Using Sentiment Analysis of Customer
Get PDFAppropriate forecasting of sales can lead to significant revenue gains for any organization, as it allows them to plan their funding, arrange infrastructure, manage the supply chain, and anticipate profits accordingly. However, sales forecasting depends on various factors, such as product quality, market trends, economic conditions, competition, and customer behavior, and it has become even more challenging with the rise of online retailing. In today’s era, especially for online retailing, customer feedback plays a vital role in assessing a product’s quality, as users can express their level of satisfaction through it. Customers can share their opinions using numeric values, such as ratings, and/or through text, such as reviews. Additionally, they can express their views by voting on other reviews they find most helpful, based on their own level of satisfaction. In this research, we have modified the TSMixer model for sales forecasting by amalgamating customer satisfaction levels regarding a specific product. This enhancement allows the model to account for how customer sentiment directly influences sales performance, thereby improving the accuracy of sales forecasting. Experimental results on various types of Amazon data show that, depending on the dataset and the specific error detection techniques used, the proposed model delivers a reduction in error ranging from 65% to 99% compared to established models
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
Some aspects of semirings of functions.
No full textThesis (M.Sc.)-University of KwaZulu-Natal, Westville, 2012.A well known fact of classical analysis is that the Stone- Cech compacti cation of a Tychono
space is achieved as the structure space of the commutative unitary ring of real valued continuous
functions de ned on it. An extension of this result is obtained [1] using semiring of
non-negative real valued continuous functions on the Tychono space. The present work makes
a survey of this paper and attempts to extend this to the point free domain, in which it is
shown that the collection of frame homomorphisms from the frame of non-negative reals to a
frame is a semiring again
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
- …
