1,720,966 research outputs found
Different Approaches to Teaching a Database Course to Graduate and Undergraduate Students
No full textTeaching Self-Balancing Trees Using a Beauty Contest
Full text linkTrees data structures and their performance is one of the main topics to teach in a data structures course. Appreciating the importance of tree structure and tree height in software performance is an important concept to teach. In this paper, a simple and amusing activity is presented. It demonstrates to students the importance of a well-balanced tree by comparing the height of a binary search tree to a balanced (AVL) tree build upon some personal data to find the “prettiest” tree (minimum height). The activity highlights the fact that, irrelevant of your data sequence, a balanced tree guarantees a height of O(log n) and everyone “wins” the beauty contest
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
Fast and Memory-Efficient TFIDF Calculation for Text Analysis of Large Datasets
Full text linkTerm frequency – Inverse Document Frequency (TFIDF) is a vital first step in text analytics for information retrieval and machine learning applications. It is a memory-intensive and complex task due to the need to create and process a large sparse matrix of term frequencies, with the documents as rows and the term as columns and populate it with the term frequency of each word in each document. The standard method of storing the sparse array is the “Compressed Sparse Row” (CSR), which stores the sparse array as three one-dimensional arrays for the row id, column id, and term frequencies. We propose an alternate representation to the CSR: a list of lists (LIL) where each document is represented as its own list of tuples and each tuple storing the column id and the term frequency value. We implemented both techniques to compare their memory efficiency and speed. The new LIL representation increase the memory capacity by 52% and is only 12% slower in processing time. This enables researchers with limited processing power to be able to work on bigger text analysis datasets
Novel Recursive Technique for Finding the Optimal Solution of the Nurse Scheduling Problem
No full textSolving the Nurse Scheduling problem Is a major research area in Operations Research. Due to it being an NP-Hard problem, most researchers develop a heuristic solution for it The NSP has several constraints that need to be satisfied: several mandatory “hard” constraints that reflect hospital requirements, and several optional “soft constraints that reflect the nurses\u27 preferences. In this paper, we present a recursive solution to the problem that makes use of those constraints to shrink the search space and obtain results in a reasonable amount of lime. We present two variations of the solution. a nurse-by-nurse method of building the optimal schedule, and a shift-by-shift approach. Both variations were implemented and tested with various scenarios and the shift-by-shift solution provided much better results. The solution can also be modified easily to provide fair long-term scheduling
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
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