Co-occurrence statistics affect letter processing

Reading requires the successful encoding of letter identity and position within a visual display, a process that relies on both visual and linguistic resources. In a series of experiments, we investigate whether readers’ lifelong experience with letter co-occurrence regularities supports letter processing. Skilled readers were briefly exposed to strings of five consonants; critically, letters in position 2 and 4 were embedded in either high (B in MBL) or low (PBG) transitional probability (TP) triplets. When presented with two strings differing by the critical letter (e.g., MBLSD vs. MCLSD), participants correctly identified the right option more often in high-TP than low-TP contexts, regardless of position. Experiment II featured both a Same-Different and a Reicher-Wheeler task with response time constraints, and further qualified the contextual facilitation effect, with high-TP eliciting faster ‘same’ judgements only for letters in position 2. In a third experiment, context had no effect on Same-Different matchings with strings of pseudo-characters sharing letter low-level visual features. Our results indicate that co-occurrence statistics affect letter recognition in tasks that emphasize whole-string processing. This effect is genuinely orthographic, as it is conditional on intact letter identities, and with increasing task demands it only surfaces for letters close to word onset.

A Character Frequency based Approach to Search for Substrings of a Circular Pattern and its Conjugates in an Online Text

A fundamental problem in computational biology is to deal with circular patterns. The problem consists of finding the least certain length substrings of a pattern and its rotations in the database. In this paper, a novel method is presented to deal with circular patterns. The problem is solved using two incremental steps. First, an algorithm is provided that reports all substrings of a given linear pattern in an online text. Next, without losing efficiency, the algorithm is extended to process all circular rotations of the pattern. For a given pattern P of size M, and a text T of size N, the algorithm reports all locations in the text where a substring of Pc is found, where Pc is one of the rotations of P. For an alphabet size σ, using O(M) space, desired goals are achieved in an average O(MN/σ) time, which is O(N) for all patterns of length M ≤ σ. Traditional string processing algorithms make use of advanced data structures such as suffix trees and automaton. We show that basic data structures such as arrays can be used in the text processing algorithms without compromising the efficiency.

Computational Mining on IBICT BDTD’s Thesis and Dissertation Metadata for Supporting Social Science Research

The Brazilian Digital Library of Thesis and Dissertations (BDTD) provides essential data to support many social sciences investigations. Nevertheless, there is still a lack of computation tools tailored for helping extract and analyze the necessary information from the BDTD library. In this paper, we discuss the development of computational solutions to answer questions from a particular social sciences research using metadata from BDTD. The solutions involve the integration of data processing and presentation techniques, such as string-processing algorithms, knowledge graphs and information visualizations. All programming codes implemented at the scope of the project are available for helping other researchers. The paper also highlights the importance of having researchers from Social Science and Computer Science working together, what motivates future collaborations in these areas.

String processing model for knowledge-driven systems

The purpose of the work is to confirm experimentally theoretical estimates for time complexity of operations of the string processing model linked with the metric space for solving data processing problems in knowledge-driven systems including the research and comparison of the operation characteristics of these operations with the characteristics of similar operations for the most relevant data structures. Integral and unit testing were used to obtain the results of the performed computational experiments and verify their correctness. The C \ C++ implementation of operations of the string processing model was tested. The paper gives definitions of concepts necessary for the calculation of metric features calculated over strings. As a result of the experiments, theoretical estimates of the computational complexity of the implemented operations and the validity of the choice of parameters of the used data structures were confirmed, which ensures near-optimal throughput and operation time indicators of operations. According to the obtained results, the advantage is the ability to guarantee the time complexity of the string processing operations no higher than O at all stages of a life cycle of data structures used to represent strings, from their creation to destruction, which allows for high throughput in data processing and responsiveness of systems built on the basis of the implemented operations. In case of solving particular string processing problems and using more suitable for these cases data structures such as vector or map the implemented operations have disadvantages meaning they are inferior in terms of the amount of data processed per time unit. The string processing model is focused on the application in knowledge-driven systems at the data management level.

Basics of algorithmization and programming in Microsoft Visual Basic

This tutorial covers the basics of algorithmization and programming in Microsoft Visual Basic. Contains a description of such traditional material necessary for learning the basics of algorithmization as the operation of linear, branching, and cyclic structures, processing one-dimensional and two-dimensional arrays, programming using functions and procedures, string processing, and so on. We discuss the data types used in VB, review the main controls of the programming environment, and pay attention to data input and output methods. It also describes how to work with graphics based on the GDI+interface. Meets the requirements of the Federal state educational standards of secondary professional education of the latest generation. It can be used by students and teachers of secondary professional and higher educational institutions.