• The Journal of the Korea institute of electronic communication sciences
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• v.16 no.2
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• pp.347-354
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• 2021

In the equipment industry such as chemical plants, high temperature, high pressure, and toxic fluids move between various facilities through piping. The movement and damage of pipes due to changes in the surrounding environment such as temperature changes, vibrations, earthquakes, and ground subsidence often lead to major accidents involving personal injury. In order to prevent such an accident, various types of expansion joints are used to absorb and supplement various shocks applied to the pipe to prevent accidents in advance. Therefore, it is very important to measure the deformation of the used expansion joint and predict its lifespan to prevent a major accident. In this paper, the deformation of the expansion joint was understood as a kind of motion, and the change was measured using a Hall Effect Sensor and a 9-Axis Sensor. In addition, we studied a system that can predict the deformation of expansion joints by collecting and analyzing the measured data using a general-purpose microcomputer (Arduino Board) and C language.

• Journal of Digital Convergence
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• v.16 no.12
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• pp.309-315
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• 2018

In this paper, propose an efficient arc detection and control method to achieve fast machining speed, improved precision and surface roughness in discharge machining, especially for carbide and hard material processing and metal processing using discharge phenomenon as energy. A single discharge waveform is divided into three sections of Td (Time-Delay), Ton (Time-on) and Toff (Time-off) and the gate control timing is simulated using the HDL language. In this paper, we analyze the effect of the gap between the electrode and the workpiece on the machining results by determining the operation of the servo mechanism by sampling the Td section through the comparator circuit. As a result of the analysis, the Td section of the formed waveform was more precisely sampled at a high speed and the results were improved when applied to the gap control between the electrode and the workpiece.

• Journal of The Korean Association of Information Education
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• v.23 no.1
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• pp.1-8
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• 2019

In order to provide basic data necessary for developing a curriculum to enhance SW education for elementary school teacher students, a questionnaire survey was conducted on 1,260 students at G National University of Education. The results are summarized as follows. First, it is necessary to improve class time of SW education for the college students and revise the SW curriculum to improve SW education capacity for teacher students. Second, in the liberal arts course, it is necessary to develop the teaching and learning materials and the textbooks using various software. Third, in the major course, the Subject Pedagogy programs should be expanded rather than the subject content programs. Fourth, in the specialization course, the programming language education focusing on the Entry and EPL should be strengthened so that it can be linked with the elementary school curriculum. In addition, it is necessary to expand the choice of subjects for the students by reducing the number of required courses and increasing the number of elective courses.

• Journal of The Korean Association of Information Education
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• v.23 no.4
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• pp.329-341
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• 2019

Computer education in universities has been expanded and specialized from ICT-based education in recent years to software education such as computational thinking and programming. Especially, as the 4th Industrial Revolution is emphasized in all fields of society, software education, which is its core, is being applied as an essential liberal arts course in universities. In the case of basic SW education for all students, it is necessary to provide differentiated education that is suitable for students because their special characteristics are different. In this study, we conducted a basic SW course for general liberal arts at A-university in Seoul and analyzed the survey data from 4,927 students for about 3 years, and classified the major series and searched the appropriate education method for each subdivided group. Through the analysis, we were able to find characteristic groups such as business and commerce, art and sports major. Finally, six groups for basic-SW education are presented. Educational directions such as programming language and level of difficulty setting suitable for differentiated education are presented for each group.

• Journal of Convergence for Information Technology
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• v.9 no.9
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• pp.1-12
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• 2019

A dialog system becomes a new way of communication between human and computer. The dialog system takes human voice as an input, and gives a proper response in voice or perform an action. Although there are several well-known products of dialog system (e.g., Amazon Echo, Naver Wave), they commonly suffer from a problem of out-of-domain utterances. If it poorly detects out-of-domain utterances, then it will significantly harm the user satisfactory. There have been some studies aimed at solving this problem, but it is still necessary to study about this intensively. In this paper, we give an overview of the previous studies of out-of-domain detection in terms of three point of view: dataset, feature, and method. As there were relatively smaller studies of this topic due to the lack of datasets, we believe that the most important next research step is to construct and share a large dataset for dialog system, and thereafter try state-of-the-art techniques upon the dataset.

• Geomechanics and Engineering
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• v.18 no.2
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• pp.205-213
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• 2019

A calculation model of reservoir pressure field distribution around multiple production wells in a heavy oil reservoir is established, which can overcome the unreasonable uniform-pressure value calculated by the traditional mathematical model in the multiwell mining areas. A calculating program is developed based on the deduced equations by using Visual Basic computer language. Based on the proposed mathematical model, the effects of drainage rate and formation permeability on the distribution of reservoir pressure are studied. Results show that the reservoir pressure drops most at the wellbore. The farther the distance away from the borehole, the sparser the isobaric lines distribute. Increasing drainage rate results in decreasing reservoir pressure and bottom-hole pressure, especially the latter. The permeability has a significant effect on bottom hole pressure. The study provides a reference basis for studying the dynamic pressure field distribution before thermal recovery technology in heavy oilfield and optimizing construction parameters.

• Journal of Internet Computing and Services
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• v.20 no.1
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• pp.57-65
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• 2019

In the case of Domeggook B2B online shopping malls, it has a market share of over 70% with more than 2 million members and 800,000 items are sold per one day. However, since the same or similar items are stored and registered in different catalog entries, it is difficult for the buyer to search for items, and problems are also encountered in managing B2B large shopping malls. Therefore, in this study, we developed a catalog entry auto classification and recommendation system for products by using semi-supervised machine learning method based on previous huge shopping mall purchase information. Specifically, when the seller enters the item registration information in the form of natural language, KoNLPy morphological analysis process is performed, and the Naïve Bayes classification method is applied to implement a system that automatically recommends the most suitable catalog information for the article. As a result, it was possible to improve both the search speed and total sales of shopping mall by building accuracy in catalog entry efficiently.

• The Mathematical Education
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• v.58 no.2
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• pp.319-335
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• 2019

In this paper, we examine the effectiveness of calculation according to automation, which is one of Computational Thinking, by coding the conceptual process into Python language, focusing on the concept of divisibility in elementary school textbooks. The educational implications of these considerations are as follows. First, it is possible to make a field of learning that can revise the new mathematical concept through the opportunity to reinterpret the Conceptual Thinking learned in school mathematics from the perspective of Computational Thinking. Second, from the analysis of college students, it can be seen that many students do not have mathematical concepts in terms of efficiency of computation related to the divisibility. This phenomenon is a characteristic of the mathematics curriculum that emphasizes concepts. Therefore, it is necessary to study new mathematical concepts when considering the aspect of utilization. Third, all algorithms related to the concept of divisibility covered in elementary mathematics textbooks can be found to contain the notion of iteration in terms of automation, but little recursive activity can be found. Considering that recursive thinking is frequently used with repetitive thinking in terms of automation (in Computational Thinking), it is necessary to consider low level recursive activities at elementary school. Finally, it is necessary to think about mathematical Conceptual Thinking from the point of view of Computational Thinking, and conversely, to extract mathematical concepts from computer science's Computational Thinking.

• Phonetics and Speech Sciences
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• v.13 no.3
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• pp.71-78
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• 2021

Most neural-network-based speech synthesis models utilize neural vocoders to convert mel-scaled spectrograms into high-quality, human-like voices. However, neural vocoders combined with mel-scaled spectrogram prediction models demand considerable computer memory and time during the training phase and are subject to slow inference speeds in an environment where GPU is not used. This problem does not arise in linear spectrogram prediction models, as they do not use neural vocoders, but these models suffer from low voice quality. As a solution, this paper proposes a Tacotron 2 and Transformer-based linear spectrogram prediction model that produces high-quality speech and does not use neural vocoders. Experiments suggest that this model can serve as the foundation of a high-quality text-to-speech model with fast inference speed.

• Journal of Convergence for Information Technology
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• v.11 no.5
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• pp.138-149
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• 2021

Our society is developing exponentially, but schools are not keeping up with the pace of society's development, and they are not providing digital literacy education suitable for the growth and development of students. Thus, this study identified the actual conditions and problems of digital literacy education at school sites and sought the direction of development of digital literacy education. By identifying the current state of schools in which the 2015 curriculum is operated, we sought the direction of the development of digital literacy education for our school. First, old digital devices should be replaced, laptops or smart devices should be provided for each student, and internet access should be available throughout the school. Second, digital literacy education should be provided to teachers by providing various training opportunities.Third, coding education where you can express what you think as logical thinking, Software training should increase the level of the algorithmic domain that shows the computational thinking process of discovering problems and automating a given problem into a computer programming language, there is enough robot that can be seen operating the program, digital parish will need to be delivered.