1,721,009 research outputs found
Software Cost Estimation : A State-Of-The-Art Statistical and Visualization Approach for Missing Data
No full textSoftware Cost Estimation (SCE) is a critical phase in software development projects. A common problem in building software cost models is that the available datasets contain projects with lots of missing categorical data. There are several techniques for handling missing data in the context of SCE. The purpose of this paper is to show a state-of-art statistical and visualization approach of evaluating and comparing the effect of missing data on the accuracy of cost estimation models. Five missing data techniques were used: Multinomial Logistic Regression, Listwise Deletion, Mean Imputation, Expectation Maximization and Regression Imputation and compared with respect to their effect on the prediction accuracy of a least squares regression cost model. The evaluation is based on various expressions of the prediction error. The comparisons are conducted using statistical tests, resampling techniques and visualization tools like the Regression Error Characteristic curves.</p
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
Statistical methods in information systems project planning
No full textThe term Information System (IT) is generic and refers to a system that includes all the functions of an organization. In this particular research area, the key component of an information system is the software used in the organization to store and process data but also the automation of the IT processes. Therefore, the Information System is a product that should cover various specifications and quality requirements related to the needs of its application domain.Τhis thesis mainly focuses in the is the definition of priorities in the different software requirements known as requirements prioritization. The large number of requirements and the different views of the employees participating in the survey that define what are the most important and therefore deserve higher priority, make the problem of decision-making extremely difficult and complex. Those data are collected from questionnaires in which special methods are applied (Cumulative Voting). The questionnaires are completed by the stakeholders in such research containing their views coded into numerical "scores" for the prioritization of various requirements. Although the simple sum of the scores from all participants shows which requirements are the most important, the overall information that exists in the data conceals considerable variability. Τhe variables of all the data sets are limited and correlated. In general the normalized form of these data consists of vectors (in the interval [0,1]) that are sum up to one. Special methods of multivariate analysis required for such data, since the usual regularity assumptions and independence does not apply here. These methods will have to answer to several questions related to the level of alignment between the stakeholders, the conflicting nature of the requirements, with the grouping of views and the comparison of views among the inherit groups of stakeholders. Τhe management of software projects, the appropriate allocation of resources in the various software phases in relation to the investigation of the high complexity of the distribution of effort are interesting problems which have not been studied with multivariate methods yet. In this thesis multivariate statistical methods were applied, that have never been used so far in the literature. For instance the statistical analysis framework known as Compositional Data Analysis (CoDA). CoDA was used in data sets which contained proportions similar to what we get from the priority assignment procedures. This analysis includes a wide variety of techniques that aspire to answer critical questions about the priorities of quality requirements as defined by people who behave and express an opinion according to the position they occupy in an organization and the perspective from which the prioritize the quality of the software. The research effort and the statistical analysis through this thesis tried to focus on the human factor and to explore the differences and similarities in views that ultimately determine the quality of a product.Τhe research conducted as part of this thesis had a goal: to use advanced statistical methods to problems of quality that we usually face in information systems.Ο όρος Πληροφοριακό Σύστημα (Information System), αναφέρεται σε ένα σύστημα που περικλείει όλες τις λειτουργίες ενός οργανισμού. Το βασικό συστατικό του είναι το λογισμικό που χρησιμοποιείται σε έναν οργανισμό για την αποθήκευση και επεξεργασία δεδομένων και την αυτοματοποίηση πληροφοριακών διαδικασιών. Η πολυπλοκότητα της δομής του λογισμικού, δημιουργούν ένα εξαιρετικά σύνθετο πρόβλημα που απαιτεί προηγμένες μεθόδους ανάλυσης και έρευνας.Η περιοχή στην οποία εστιάζεται κυρίως η παρούσα διδακτορική διατριβή είναι ο καθορισμός προτεραιοτήτων στις διάφορες απαιτήσεις του λογισμικού (requirements prioritization). Ο μεγάλος αριθμός των απαιτήσεων και οι διαφορετικές απόψεις των εργαζομένων που συμμετέχουν στην έρευνα και ορίζουν ποιες είναι οι πιο σημαντικές και επομένως αξίζουν υψηλότερη προτεραιότητα κάνουν το πρόβλημα της λήψης αποφάσεων ιδιαίτερα δύσκολο και πολύπλοκο. Τα δεδομένα που συλλέγονται από ειδικά ερωτηματολόγια (Cumulative Voting) που συμπληρώνουν οι συμμετέχοντες σε μια τέτοια έρευνα περιέχουν τις απόψεις τους κωδικοποιημένες σε αριθμητικές βαθμολογίες για την απόδοση προτεραιοτήτων στις διάφορες απαιτήσεις. Παρόλο που η απλή άθροιση των βαθμολογιών από όλους τους συμμετέχοντες δείχνει ποιες απαιτήσεις είναι οι πιο σημαντικές, η συνολική πληροφορία που υπάρχει στα δεδομένα κρύβει μεγάλη μεταβλητότητα και συσχετίσεις και δεν έχει μελετηθεί συστηματικά με στατιστικές μεθόδους. Οι μεταβλητές του συνόλου των δεδομένων, από τα συγκεκριμένα σχήματα ψηφοφορίας, είναι φραγμένες και μεταξύ τους συσχετισμένες. Στη γενική τους κανονικοποιημένη μορφή τα δεδομένα αυτά αποτελούνται από διανύσματα ποσοστών (στο διάστημα [0,1]) που αθροίζονται στη μονάδα. Επομένως απαιτούνται ειδικές μέθοδοι πολυμεταβλητής ανάλυσης για τέτοιου είδους δεδομένα, αφού οι συνήθεις υποθέσεις κανονικότητας και ανεξαρτησίας δεν ισχύουν εδώ. Οι μέθοδοι αυτές θα πρέπει να απαντήσουν σε διάφορα ερωτήματα που σχετίζονται με το πόσο συμφωνούν μεταξύ τους οι συμμετέχοντες, με την αντικρουόμενη φύση των απαιτήσεων, με την ομαδοποίηση των απόψεων και με τη σύγκριση των απόψεων ανάμεσα σε προκαθορισμένες ομάδες των ενδιαφερομένων. Στη διαχείριση έργων λογισμικού η κατάλληλη κατανομή των πόρων στις διάφορες φάσεις ανάπτυξης του έργου σε σχέση με τη διερεύνηση της υψηλής πολυπλοκότητας της κατανομής της προσπάθειας (effort) αποτελούν ενδιαφέροντα προβλήματα που δεν είχαν μελετηθεί με πολυμεταβλητές μεθόδους. Στην διδακτορική αυτή διατριβή εφαρμόστηκαν πολυμεταβλητές στατιστικές μέθοδοι ειδικές για δεδομένα ανάθεσης προτεραιοτήτων που δεν έχουν χρησιμοποιηθεί ποτέ μέχρι τώρα στη διεθνή βιβλιογραφία. Ενδεικτικά αναφέρεται η χρήση του πλαισίου στατιστικών αναλύσεων Ανάλυση Δεδομένων Σύστασης (Compositional Data Analysis, CoDA) και χρησιμοποιείται για δεδομένα ποσοστών παρόμοια με αυτά που λαμβάνονται από τις διαδικασίες ανάθεσης προτεραιοτήτων. Η ερευνητική προσπάθεια μέσα από αυτή τη διατριβή και από την στατιστική ανάλυση προσπάθησε να δώσει έμφαση στον ανθρώπινο παράγοντα και να διερευνήσει τις διαφορές και τις ομοιότητες στις απόψεις που τελικά καθορίζουν την ποιότητα ενός προϊόντος.Η έρευνα που διεξήχθη στα πλαίσια της παρούσας διδακτορικής διατριβής είχε ως στόχο τη χρήση προηγμένων στατιστικών μεθόδων και μοντέλων σε προβλήματα ποιότητας πληροφοριακών συστημάτων
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
Visualizing CI’s role in software quality attribute evaluation : A Roadmap for Using Continuous Integration Environments
No full textQuality attributes of software systems, also known as system qualities, such as performance, security, and scalability, continue to grow in importance in industrial practice. The evaluation of quality attributes is critical to software development since optimizing a software system’s core attributes can provide marketing advantage and set a product apart from its competitors. Many existing studies of unsuccessful development projects report that lack of quality attribute evaluation is often a contributing factor of project failure. Therefore, continuous quality attribute evaluation, throughout the development process, is needed to ensure customers’ expectations and demands are met. Manual evaluation of software attributes is common in many software development companies, but it has proven to be insufficient in meeting the demands of rapid releases and high-quality expectations from customers. Automated practices have therefore gained widespread popularity as a solution to enhance efficiency, reduce costs, and increase accuracy compared to manual evaluation. One way to automate the evaluation is using continuous integration (CI) environments. The CI environment provides several benefits, such as fast feedback on code quality, early detection of quality defects, and visualization of system quality trends. As such, these environments inherently offer organizations the opportunity to continuously monitor the quality of their software systems. However, an immature automation process can result in negative outcomes, such as cost and schedule overruns, slow feedback loops, and delayed releases. To improve the evaluation process, prior studies have investigated different key areas, including knowledge, processes, tools, and metrics. While leveraging these areas can have a positive impact on quality evaluation, to the best of our knowledge, there is a lack of frameworks that link CI environment knowledge, metrics, and evolution together. In this article, we aim to fill this gap by presenting the state-of-practice of using CI environments for the evaluation of quality attributes. This is achieved through an industrial study at four partner companies. Study results show that metrics acquired from CI components have a positive effect on evaluating quality requirements. Through analyzing these results, we propose a model by providing guidelines to mature existing CI environments that organizations can use for quality improvements. As such, we claim the following contributions of this study: A generic model of how CI environments contribute to quality attribute evaluation. Empirical evidence that demonstrates how CI components can be used to produce data supporting the evaluation of quality attributes with metrics. A model, derived from the study results, which provides decision support to evolve software quality evaluation through CI environments over time. © 2024 Owner/Author
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
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