• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.8
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• pp.557-562
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• 2020

In the non-face-to-face learning environment forced into effect by the COVID-19 pandemic, online learning is being adopted as a major educational technique. Given the lack of research on how online learning patterns affect academic performance, this study focuses on the number and duration of online video learning sessions as a major factor based on midterm and final exams, and with a formative assessment for each type of learning. The correlation of the learning effects was analyzed. The analysis focused on computer programming subjects, which are among the most difficult liberal arts subjects for arts and science students at the university level. The analysis of cases of actual students showed no correlation among weekly formative assessments, the number of learning sessions, and the learning duration. On the other hand, the number of learning sessions (r=.39 p<0.05) and learning duration (r=.42 p<0.05) were correlated with the midterm and final exams. Elements, such as SMS text, bulletin board, and e-mail, were excluded from the analysis because not all students have access to them. Therefore, the results can be improved if future analysis of the students' learning patterns in a non-face-to-face lecture environment is performed considering more factors/elements and the learners' needs.

• Journal of KIISE:Software and Applications
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• v.36 no.4
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• pp.253-260
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• 2009

Many algorithms for computer vision and pattern recognition have recently been implemented on GPU (graphic processing unit) for faster computational times. However, the implementation has two problems. First, the programmer should master the fundamentals of the graphics shading languages that require the prior knowledge on computer graphics. Second, in a job that needs much cooperation between CPU and GPU, which is usual in image processing and pattern recognition contrary to the graphic area, CPU should generate raw feature data for GPU processing as much as possible to effectively utilize GPU performance. This paper proposes more quick and efficient implementation of neural networks on both GPU and multi-core CPU. We use CUDA (compute unified device architecture) that can be easily programmed due to its simple C language-like style instead of GPU to solve the first problem. Moreover, OpenMP (Open Multi-Processing) is used to concurrently process multiple data with single instruction on multi-core CPU, which results in effectively utilizing the memories of GPU. In the experiments, we implemented neural networks-based text extraction system using the proposed architecture, and the computational times showed about 15 times faster than implementation on only GPU without OpenMP.

• The KIPS Transactions:PartA
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• v.9A no.3
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• pp.387-398
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• 2002

As whole genome sequences of many organisms have been revealed by small-scale genome projects, the intensive research on individual genes and their functions has been performed. However on-memory algorithms are inefficient to analysis of whole genome sequences, since the size of individual whole genome is from several million base pairs to hundreds billion base pairs. In order to effectively manipulate the huge sequence data, it is necessary to use the indexed data structure for external memory. In this paper, we introduce a workbench system for analysis and visualization of whole genome sequence using string B-tree that is suitable for analysis of huge data. This system consists of two parts : analysis query part and visualization part. Query system supports various transactions such as sequence search, k-occurrence, and k-mer analysis. Visualization system helps biological scientist to easily understand whole structure and specificity by many kinds of visualization such as whole genome sequence, annotation, CGR (Chaos Game Representation), k-mer, and RWP (Random Walk Plot). One can find the relations among organisms, predict the genes in a genome, and research on the function of junk DNA using our workbench.

• Journal of Educational Research in Mathematics
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• v.17 no.2
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• pp.163-177
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• 2007

Studies on mathematically gifted students have been conducted following Krutetskii. There still exists a necessity for a more detailed research on how these students' mathematical competence is actually displayed during the problem solving process. In this study, it was attempted to analyse the algebraic thinking process in the problem solving a peg puzzle in which 4 mathematically gifted students, who belong to the upper 0.01% group in their grade of elementary school in Korea. They solved and generalized the straight line peg puzzle. Mathematically gifted elementary school students had the tendency to find a general structure using generic examples rather than find inductive rules. They did not have difficulty in expressing their thoughts in letter expressions and in expressing their answers in written language; and though they could estimate general patterns while performing generalization of two factors, it was revealed that not all of them can solve the general formula of two factors. In addition, in the process of discovering a general pattern, it was confirmed that they prefer using diagrams to manipulating concrete objects or using tables. But as to whether or not they verify their generalization results using generalized concrete cases, individual difference was found. From this fact it was confirmed that repeated experiments, on the relationship between a child's generalization ability and his/her behavioral pattern that verifies his/her generalization result through application to a concrete case, are necessary.

• Journal of Convergence for Information Technology
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• v.12 no.2
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• pp.30-36
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• 2022

In this paper, when the lighting and communication functions of the visible light communication system are used at the same time, we propose a technique to reduce the dimming level and flicker of the lighting. Visible light communication must satisfy both communication and lighting performance. However, the existing data code method results in reducing the brightness of the entire lighting. This causes deterioration of lighting performance and flicker phenomenon. To solve this problem, in this paper, we propose an adaptive learning code allocation technique that allocates binary codes to transmitted characters and optimizes and matches the binary codes allocated according to the frequency of occurrence of alphabets in character strings. Through this, we studied a technique that can faithfully play the role of lighting as well as communication function by allocating codes so that the 'OFF' pattern does not occur continuously while maintaining the maximum dimming level of each character string. As a result of the performance evaluation, the frequency of occurrence of '1' increased significantly without significantly affecting the overall communication performance, and on the contrary, the frequency of consecutive '0' decreased, indicating that the lighting performance of the system was greatly improved.

• The KIPS Transactions:PartC
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• v.19C no.3
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• pp.167-172
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• 2012

Mobile phone devices and memory card can be robbed and lost due to the carelessness that might be caused to leak personal information, and also company's confidential information can be disclosed. Therefore, the importance of user authentication to protect personal information is increasing exponentially. However, there are the limitations that criminals could easily obtain and abuse information about individuals, because the input method of personal identification number or the input method of password might not be safe for Shoulder Surfing Attack(SSA). Although various biometric identification methods were suggested to obstruct the SSA, it is the fact that they also have some faults due to the inconvenience to use in mobile environments. In this study, more complemented service for the user authentication was proposed by applying Keystroke method in the mobile environments to make up for the faults of existing biometric identification method. Lastly, the effectiveness and validity of this study were confirmed through experimental evaluations.

• The Transactions of the Korea Information Processing Society
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• v.7 no.12
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• pp.3762-3774
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• 2000

The advances of computer hardware and information processing technologies raise the needs of multimedia information retrieval systems. Up to date. multimedia information systems have been developed for text information and image information. Nowadays. the multimedia information systems for video and audio information. especially for musical information have been grown up more and more. In recent music information retrieval systems. not only the information retrieval based on meta-information such like composer and title but also the content-based information retrieval is supported. The content-based information retrieval in music information retrieval systems utilize the similarity value between the user query and the music information stored in music database. In tbis paper. hence. we developed a similarity computation algorithm in which the pitches and lengths of each corresponding pair of notes are used as the fundamental factors for similarity computation between musical information. We also make an experiment of the proposed algorithm to validate its appropriateness. From the experimental results. the proposed similarity computation algorithm is shown to be able to correctly check whether two music files are analogous to each other or not based on melodies.

• Journal for History of Mathematics
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• v.23 no.4
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• pp.101-122
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• 2010

Chinese Taipei won the first place at the mathematics achievement of TIMSS 2007. Especially, there was a significant difference in the percentage of correct answers between Chinese Taipei and Korea, and Chinese Taipei' percentage of correct answers was higher than Korea. This study compared the education system, mathematics instruction environment, and instructional activities of two countries. And for algebra, curriculum and textbooks were compared between two countries based on TIMSS 2007 framework. It was found that Chinese Taipei emphasized homework and test, and MCFL of that was low. Their textbook was formal, and induced the hasty abstraction, Also, some themes were introduced earlier than Korea and repeated across different grades.

• Journal of the Korean Geographical Society
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• v.48 no.2
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• pp.184-203
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• 2013

This study analyzes the variability of Korean summer rainfall associated with the tropical low-frequency oscillation using long-term observation data. From the EOF analysis, the first mode showed opposite phase between the South and the North Korea with the regime shift in rainfall variability since the mid-1990s. The summer precipitation over South Korea tends to increase in southern part during strong El Ni$\tilde{n}$o where the warm sea surface temperature extends to far eastern tropical Pacific. In weak La Ni$\tilde{n}$a, the increased precipitation directly influences from the western tropical Pacific to the mid-latitude. In June, the rainfall over South Korea is positively correlated with the Indian Summer Monsoon while in July, it is negatively correlated with the Western North Pacific Summer Monsoon. In August, highly negative correlation between the rainfall over South Korea and the Indian Summer Monsoon is found.

• The Journal of the Korea institute of electronic communication sciences
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• v.13 no.5
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• pp.987-994
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• 2018

In this paper, an automatic transmission system of traffic information is presented. Here, a traffic event is defined as an obstacle to an emergency vehicle such as an ambulance or a fire truck. When a traffic event is detected from a video recorded by a black box installed in a vehicle, the implemented system automatically transmits a proof image and corresponding information to the control center through an e-mail. For this purpose, we realize an algorithm of identifying the numbers and a character from the license plate, and an algorithm for determining the occurrence of a traffic event. To report the event, a function for automatic transmission of the text and image files through e-mail and file transfer protocol (FTP) is also appended. Therefore, if the traffic event is extended and applied to the presented system, it will be possible to establish a convenient reporting system for the violation of various traffic regulations. In addition, it will contribute to significantly reduce the number of traffic violations against the regulations.