1,720,964 research outputs found
An Empirical Assessment of Customer Lifetime Value Models within Data Mining
Get PDFCustomer lifetime value has been of significant importance to marketing researchers and practitioners in specifying the importance level of each customer. By means of segmentation which could be carried out using value-based characteristics it is indeed possible to develop tailored strategies for customers. In fact, approaches like data mining can facilitate extraction of critical customer knowledge for enhanced decision making. Although the literature has several analytical lifetime value models, comparative assessment of the existing models especially within the context of data mining seems a missing component. The aim of this paper is to compare two different customer lifetime value models within data mining. The evaluation was carried out within the context of customer segmentation using a database of a company operating in retail sector. The results indicated that two models yield the same segmentation structure and no statistical differences detected on the select control variables. However, the remaining model produced rather different segmentation results than their peers and it was possible to identify the most lucrative model according to the statistical analyses that were carried out on the select control variables
Unilateral subcostal anterior quadratus lumborum block versus intrathecal morphine for postoperative pain in laparoscopic nephrectomy: a randomized controlled trial
No full textBackground: Intrathecal morphine (ITM) offers effective analgesia after laparoscopic nephrectomy but may cause side effects. The anterior subcostal quadratus lumborum (QL) block has been proposed as a safer alternative. This study evaluated whether anterior subcostal QL block is non-inferior to ITM in reducing postoperative opioid use. Methods: This single-center, randomized, observer-blinded, non-inferiority trial allocated 80 adult patients undergoing elective laparoscopic nephrectomy to receive single-injection unilateral anterior subcostal QL block (0.25% bupivacaine (0.4 mL/kg) containing epinephrine 1:400,000) or spinal anesthesia with 5 mcg/kg ITM (maximum 200 mcg) plus 7.5 mg isobaric bupivacaine. The primary outcome was the 24-hour cumulative intravenous morphine milligram equivalent (MME). Pain scores were recorded at rest and during activity at 0, 3, 6, 12, and 24 hours postoperatively. Patient satisfaction, recovery quality, and adverse effects were also evaluated. Results: The median difference in 24 hours intravenous MME consumption between anterior subcostal QL block and ITM was 9.5 mg (95% CI 7 to 12; p<0.001), exceeding the non-inferiority margin. Patients with ITM reported lower pain scores and greater satisfaction at 24 hours (median (Q1-Q3), ITM 108 (102.25-113.5) vs anterior subcostal QL block 75.5 (58-100)) and discharge (ITM 117 (115-123.75) vs anterior subcostal QL block 94 (77-110); p<0.001). However, no between-group differences were observed in 30-day complication rates, including the Clavien-Dindo and Comprehensive Complication Index scores. Adverse effects, such as nausea, pruritus, and respiratory events, were comparable. Conclusions: Although designed as a non-inferiority trial, anterior subcostal QL block did not meet the threshold. While ITM resulted in lower opioid use, the study was not powered to establish superiority. Anterior subcostal QL block may be considered for patients at risk of ITM-related respiratory depression; however, its inconsistent cranial spread and limited visceral analgesia may explain its lower efficacy. Caution is also required in anticoagulated patients because of the deep anatomical location of the block. Trial registration number: ClinicalTrials.gov: NCT06630858
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
A Novel Agent-Supported Academic Online Examination System
No full textProper execution of exams aimed at assessment & evaluation is of critical importance in Learning Management Systems (LMS). Problems arising from human-centered errors or technical difficulties may lead to questioning of exams, and thus of reliability and efficiency of the distance education systems. Online examination system architecture proposed in this paper provides for integrated management of main functions such as question pool creation and update, exam authoring, execution and evaluation, and management of the feedbacks from students, along with ensuring use of analysis reports related to the questions and exams created by an intelligent agent in the decision-making processes. After conducting analyses on the distance education (DE) system of Sakarya University, it was found that the proposed intelligent agent supported online exam system detects the problems that arise to a large extent and enables the instructors to decide more easily in a shorter time. This system, which is possible to expand with its flexible structure to include additional intelligent features with the aim of resolving different problems, can also be adapted to different institutions that use online examination systems
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
- …
