• Journal of the Korean Society of Earth Science Education
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• v.5 no.2
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• pp.139-147
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• 2012

The purpose of this study was to explain how extraordinary the scientific technology or our ancestor was from the modern perspective by remodeling the most unique astronomical instrument, So-ganui (小簡儀), developed in the Sejong Period (世宗時代) after being examined with contemporary and the principles of the science and observational technology would be properly understood and measured directly. When measuring the altitude of the sun and azimuth using So-ganui, it was adjusted with the horizontal coordinate system and measured using Jipyeonghwan (地平環), Ipeunhwan (立運環) and Guyhyeong (窺衡). Based such measuring principles, the measurement accuracy proposed using So-ganui are as follows. The remodeled So-ganui produced approximately ${\pm}0.29$ degrees error on average at high altitude while in measuring the azimuth degrees, there was difference of ${\pm}0.35$ degrees. Since the theoretically, the measurement error for So-ganui was ${\pm}0.5$ degrees, the remodeled So-ganui could accurately measure at the high altitude compared to So-ganui from the Sejong period. In the study, So-ganui, which has disappeared, has been remodeled in modern perspective to be used as the educational material to accurately understand the principles of science and measurement technology from the Sejong period. The findings could contribute to raising the reputation in the astronomical observations from the documents from the Sejong period. Furthermore, this study has materialized the celestial and sky our ancestors have viewed with the observational principles of their times, on the computer screen via a webcam, bringing out interest in the traditional science for the students.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.16 no.2
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• pp.49-54
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• 2016

In this paper, we propose an Arduino-based effective home security monitoring system. Proposed home security monitoring system consists of arduino which is inexpensive main processor, ultrasonic sensor and human body detection sensor to detect whether someone breaks into home. Data from ultrasonic sensor and human body detection sensor are transmitted to web server via ethernet shield connected to arduino. Web server checks whether someone breaks into home by using stored data from ultrasonic sensor and human body detection sensor. Snapshot is photographed via webcam connected by using JQuery. Photographed snapshot is stored in web server as image file. A user can monitor in web or smart device environment by using HTML5, CSS and Canvas. When examining efficiency of proposed home security monitoring system, it was found that proposed system is easier to be made than existing home security system and is cost effective by using arduino and is efficient and convenient and stable as it enables a user to handle an error in person and it uses reliable data.

• Journal of Digital Contents Society
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• v.18 no.8
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• pp.1603-1613
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• 2017

This paper proposes a method for effectively segmenting the hand region using a widely popular RGB color-based webcam. This performs the empirical preprocessing method four times to remove the noise. First, we use Gaussian smoothing to remove the overall image noise. Next, the RGB image is converted into the HSV and the YCbCr color model, and global fixed binarization is performed based on the statistical value for each color model, and the noise is removed by the bitwise-OR operation. Then, RDP and flood fill algorithms are used to perform contour approximation and inner area fill operations to remove noise. Finally, ROI (hand region) is selected by eliminating noise through morphological operation and determining a threshold value proportional to the image size. This study focuses on the noise reduction and can be used as a base technology of gesture recognition application.

• Geophysics and Geophysical Exploration
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• v.17 no.2
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• pp.58-65
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• 2014

We studied the source mechanisms of very-long-period event recorded at seismic station WIZ near White Island Volcano, New Zealand on August 4, 2012. Since seismic data at only one station were available, we conducted moment tensor inversion using three simplified models (explosion, crack, and pipe models). To constrain the moment tensor solution of seismic event, we computed synthetic data for each model to compare with observed data. Type and orientation for the best model is a crack at a depth of 1600 m with a dip of $80^{\circ}NE$ and a strike of $N80^{\circ}W$. We interpret that a deep explosion may have opened a crack for gases to escape, and the upward gas flow triggered the surface explosions four hours later as confirmed by a webcam. The interpretation based on moment tensor inversion is consistent with previous studies of geochemical data of the volcanic island.

• Journal of Korea Society of Industrial Information Systems
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• v.19 no.5
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• pp.9-14
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• 2014

Recently, various contents using human motion are developed in computer vision and game industries. If we try to apply human motion to application programs and contents, users can experience a sense of immersion getting into it so that the users feel a high level of satisfaction from the contents. In this research, we analyze human head motion using images captured from an webcam and then we apply the result of motion recognition to a game without special devices as an interface. The proposed method, first, segments human head region using an image composed of MHI(Motion History Image) and the result of skin color detection, and then we calculate the direction and distance by the MHI sequence. In experiments, the proposed method for human head motion recognition was tested for controlling a game player. From the experimental results we proved that the proposed method can make a gammer feel more immersed into the game. Furthermore, we expect the proposed method can be an interface of a serious game for medical or rehabilitation purposes.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2010.05a
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• pp.389-392
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• 2010

In this paper, it presents to detect location using structural information of hand from the input color images on Webcam and to recognize hand gestures. In this system, based on the skin color, the image changes a binary number and labels. Within each labeled area, we can find the Maximum Inscribed Circle using Voronoi Diagram. This circle can find the center of hand. And the circle extracts hand region from analyzing the ellipse elements to relate Maximum Inscribed Circle. We use the Maximum Inscribed Circle and the ellipse elements as characteristic of hand gesture recognition. In various environments, we cannot recognize the object that have similar colors like the background colors. But the proposed algorithm has the advantage that can be effectively eliminated about it.

• Journal of the Korea Society of Computer and Information
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• v.18 no.12
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• pp.35-43
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• 2013

This paper suggests a way to implement a system that broadcasts compressed JPEG images obtained from a webcam to multiple users on their smartphones. The system was implemented to maintain a suitable image quality so that things are identifiable while using the minimal amount of data, in order to deliver as many frames as possible to as many users as possible. Also, the suggested way was applied and various tests were done, including on: the performance of the server that provides image information; the performance of the client that receives the image information and displays it on the smartphone; and the max. number of simultaneous users supported by the system. When a broadcasting system is implemented using webcams and smartphones, the results of this paper can be used in estimating the suitable system parameters depending on network performance, including the max. number of simultaneous clients supported, the client smartphone performance required, and the number of frames that can be transmitted per second.

• Journal of the Korea Convergence Society
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• v.12 no.10
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• pp.1-8
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• 2021

In online meetings and classes using webcams, the chromakey technique is a very necessary part to produce content. We proposed a technology that enables background synthesis without using a cloth for chromakey. The proposed method consists of three steps: an HSI image conversion step, a step of detecting a region changed from a background, and a step of replacing the background region with a chromakey and applying it. In the input video, the block average image of each frame is calculated, and the difference between the block average image of the background image and the block average image of the input image is used to detect the change area. The developed chromakey effect technology uses a technique of acquiring a background image without an object from a single camera and extracting only an object by distinguishing the moving object and the background. The proposed method is not only capable of processing even if the background has a variety of colors, but also has the seamless processing of the boundary lines of objects.

• The Journal of the Convergence on Culture Technology
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• v.5 no.1
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• pp.371-376
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• 2019

Creative thinking appears even before it is expressed in language, and its existence is revealed through emotion, intuition, image and body feeling before logic or linguistics rules work. In this study, Lego is intended to present experimental child interactive content that is applied with a computer vision based on image processing techniques. In the case of infants, the main purpose of this content is the development of hand muscles and the ability to implement imagination. The purpose of the analysis algorithm of the OpenCV library and the image processing using the 'VVVV' that is implemented as a 'Node' in the midst of perceptual changes in image processing technology that are representative of object recognition, and the objective is to use a webcam to film, recognize, derive results that match the analysis and produce interactive content that is completed by the user participating. Research shows what Lego children have made, and children can create things themselves and develop creativity. Furthermore, we expect to be able to infer a diverse and individualistic person's thinking based on more data.

• The Journal of the Korea institute of electronic communication sciences
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• v.19 no.1
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• pp.309-316
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• 2024

Facial recognition technology is widely used in various fields but faces challenges due to its vulnerability to fraudulent activities such as photo spoofing. Extensive research has been conducted to overcome this challenge. Most of them, however, require the use of specialized equipment like multi-modal cameras or operation in high-performance environments. In this paper, we introduce LH-FAS v2 (: Lightweight Head-pose-based Face Anti-Spoofing v2), a system designed to operate on a commercial webcam without any specialized equipment, to address the issue of facial recognition spoofing. LH-FAS v2 utilizes FSA-Net for head pose estimation and ArcFace for facial recognition, effectively assessing changes in head pose and verifying facial identity. We developed the VD4PS dataset, incorporating photo spoofing scenarios to evaluate the model's performance. The experimental results show the model's balanced accuracy and speed, indicating that head pose estimation-based facial anti-spoofing technology can be effectively used to counteract photo spoofing.