• International Journal of Naval Architecture and Ocean Engineering
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• v.6 no.1
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• pp.74-86
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• 2014

The optimization techniques are explored in the direction of arrival (DOA) estimation based on single acoustic pressure gradient vector sensor (APGVS). By analyzing the working principle and measurement errors of the APGVS, acoustic intensity approaches (AI) and the minimum variance distortionless response beamforming approach based on single APGVS (VMVDR) are deduced. The radius to wavelength ratio of the APGVS must be not bigger than 0.1 in the actual application, otherwise its DOA estimation performance will degrade significantly. To improve the robustness and estimation performance of the DOA estimation approaches based on single APGVS, two modified processing approaches based on single APGVS are presented. Simulation and lake trial results indicate that the performance of the modified approaches based on single APGVS are better than AI and VMVDR approaches based on single APGVS when the radius to wavelength ratio is not bigger than 0.1, and the two modified DOA estimation methods have excellent estimation performance when the radius to wavelength ratio is bigger than 0.1.

• The Journal of the Convergence on Culture Technology
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• v.9 no.4
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• pp.95-103
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• 2023

This paper proposes an artificial intelligence convergence education program for teaching the main concept and principle of Support Vector Machines(SVM) at elementary schools. The developed program, based on Jeju's natural environment theme, explains the decision boundary and margin of SVM by vertical and parallel from 4th grade mathematics curriculum. As a result of applying the developed program to 3rd and 5th graders, most students intuitively inferred the location of the decision boundary. The overall performance accuracy and rate of reasonable inference of 5th graders were higher. However, in the self-evaluation of understanding, the average value was higher in the 3rd grade, contrary to the actual understanding. This was due to the fact that junior learners had a greater tendency to feel satisfaction and achievement. On the other hand, senior learners presented more meaningful post-class questions based on their motivation for further exploration. We would like to find effective ways for artificial intelligence convergence education for elementary school students.

• Journal of Information Processing Systems
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• v.16 no.1
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• pp.155-170
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• 2020

Passive ranging is a critical part of machine vision measurement. Most of passive ranging methods based on machine vision use binocular technology which need strict hardware conditions and lack of universality. To measure the distance of an object placed on horizontal plane, we present a passive ranging method based on monocular vision system by smartphone. Experimental results show that given the same abscissas, the ordinatesis of the image points linearly related to their actual imaging angles. According to this principle, we first establish a depth extraction model by assuming a linear function and substituting the actual imaging angles and ordinates of the special conjugate points into the linear function. The vertical distance of the target object to the optical axis is then calculated according to imaging principle of camera, and the passive ranging can be derived by depth and vertical distance to the optical axis of target object. Experimental results show that ranging by this method has a higher accuracy compare with others based on binocular vision system. The mean relative error of the depth measurement is 0.937% when the distance is within 3 m. When it is 3-10 m, the mean relative error is 1.71%. Compared with other methods based on monocular vision system, the method does not need to calibrate before ranging and avoids the error caused by data fitting.

• International Journal of Naval Architecture and Ocean Engineering
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• v.12 no.1
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• pp.48-59
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• 2020

A traditional propeller can easily become entangled with floating objects while operating. In this paper, we present a newly developed Electromagnetic-valve-control-based Water-jet Propulsion System (ECWPS) for an unmanned surface cleaning vessel that can be flexibly controlled via a Micro Control Unit (MCU). The double-structure was adapted to the unmanned surface cleaning vessel for floating-collection missions. Computational Fluid Dynamics (CFD) software for operating effect simulation was also used to reveal the working principle of the ECWPS under different conditions. Neglecting the assembly technique, the design level, controlling strategy, and maneuvering performance of the ECWPS reached unprecedented levels. The ECWPS mainly consists of an Electromagnetic-valve Array (EA), pipeline network, control system, and water-jet source. Both CFD analyses and experimental results show that the hydraulic characteristic of the ECWPS was predicted reasonably, which has enormous practical value and development prospects.

• 한국정보교육학회:학술대회논문집
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• 2021.08a
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• pp.269-274
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• 2021

With the development of artificial intelligence, society is moving to a different world. As a result, amid growing interest in artificial intelligence education, research on how to teach artificial intelligence is also being conducted more actively in Korea. However, a lot of research is being conducted around the upper grades of elementary school, and curriculum and programs for the lower grades are insufficient. Therefore, this study developed an artificial intelligence program for lower grades. Among them, it was developed focusing on artificial intelligence image recognition. It compares image recognition methods of people, animals, and computers, identifies the characteristics of fallen leaves, and helps them understand the image recognition process of artificial intelligence by classifying them according to the characteristics of fallen leaves. I hope this program will help elementary school students understand the image recognition principle of artificial intelligence in the future.

• Journal of the Institute of Convergence Signal Processing
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• v.24 no.4
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• pp.186-191
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• 2023

Data processing techniques play a critical role in decision-making, including handling missing and outlier data, prediction, and recommendation models. This requires a clear explanation of the validity, reliability, and accuracy of all processes and results. In addition, it is necessary to solve data problems through explainable models using decision trees, inference, etc., and proceed with model lightweight by considering various types of learning. The multi-layer mining classification method that applies the sixth principle is a method that discovers multidimensional relationships between variables and attributes that occur frequently in transactions after data preprocessing. This explains how to discover significant relationships using mining on transactions and model the data through regression analysis. It develops scalable models and logistic regression models and proposes mining techniques to generate class labels through data cleansing, relevance analysis, data transformation, and data augmentation to make explanatory decisions.

• The Journal of the Korea Contents Association
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• v.22 no.4
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• pp.106-117
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• 2022

In 2021, AI basics were introduced in the high school curriculum. There are many worries that the problem of utilization-oriented education will be repeated with the introduction of artificial intelligence education rather than the principles that occurred when ICT was applied to education in the past. Most of the existing AI education platforms focus only on the use of AI. For artificial intelligence education of middle school students, there are difficulties in learning about the process by which artificial intelligence derives results and learning the principles of artificial intelligence algorithms. Recently, as the educational application of metaverse has become a hot topic, research has been started to improve learning achievement by arousing students' immersion and interest. This research developed educational game contents about decision tree algorithm using metaverse as educational contents that can be used in middle school AI education. By applying games to education, it was intended to increase students' interest and immersion in artificial intelligence, and to increase educational effectiveness. In this paper, the educational effectiveness, difficulty, and level of interest were analyzed for pre-service teachers regarding the developed game content. Based on this, a future principle-oriented artificial intelligence education method was suggested.

• Proceedings of the IEEK Conference
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• 2002.06b
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• pp.267-270
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• 2002

LCD is not very expensive and according to the principle that twisted-nematic LCD can modulate by electric signal, lots of researches been developed about many of theory, methods of design and calculating parameters effectively. In 1999 J. A. Davis et ai. proposed the method of deciding upon extraordinary and ordinary axis direction, which is based on Blazing Effect, inspect into changes of diffraction patterns. But in laboratory, it is difficulty to observe 5th or 6th diffraction pattern, and not clear in mathematical. In this paper, illuminating circular polarized beam been to TN LCD (twisted-nematic LCD), we found extraordinary axis direction with inspecting into maximum intensity distribution appeared in the side of analyzer Using Jones matrix method, we endowed with mathematical propriety.

• Structural Engineering and Mechanics
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• v.85 no.3
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• pp.393-406
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• 2023

Smart structures are those structure that could adopt some behavior to prevent instability in their responses. The recognition of stability deterioration has been performed through rigid mathematical formulations in control theory and unpredicted results could not be addressed in control systems since they are able to only work under their predefined condition. On the other hand, incorporating all affecting parameters could result in high computational cost and delay time in the response of the systems. Artificial intelligence (AI) method has shown to be a promising methodology not only in the computer science by at everyday life and in engineering problems. In the present study, we exploit the capabilities of artificial intelligence method to obtain frequency response of a smart structure. In this regard, a comprehensive development of equations is presented using Hamilton' principle and first order shear deformation theory. The equations were solved by numerical methods and the results are used to train an artificial neural network (ANN). It is demonstrated that ANN modeling could provide accurate results in comparison to the numerical solutions and it take less time than numerical solution.

• The Journal of the Korea institute of electronic communication sciences
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• v.13 no.6
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• pp.1417-1424
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• 2018

The damage caused by foot-and-mouth disease and AI has been repeated in year by year, and the actual damage is held by farmers. Currently, domestic livestock farmers' demand for foreign labor force is rapidly increasing, but the foreign management system is very inadequate, autonomous disinfection consciousness is poor and seasonally disinfest of winter is a serious situation. Thus, the exit management system, where small and medium scale farmers can purchase and install, is necessary for medium and small scaled farmer who is suffering from the pollutants and who does not have capacity to install expensive sterilization. In this paper, we propose ICT fusion combined plasma access control system which can utilize the principle of low temperature plasma lamp, to introduce disinfection system, to ensure convenience and safety that enables integrated control.