• Journal of the Korean Institute of Telematics and Electronics T
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• v.36T no.4
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• pp.123-132
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• 1999

A video conferencing system provides sharing the conference environment for geographically dispersed computer users who use the audio and video information. But the conventional video conferencing systems have some problems which are dependent on specific software and/or hardware and bound the certain platform and network environment. Furthermore the participants must know the information about other participants before joining the conference session and they have to use the same video conferencing system. This paper describes design and implementation of the video conferencing system on the WWW to solve the mentioned problems. The conference applications are transmitted from a WWW server and executed in the participants Web browsers. The participant can carry out conference services by using only the web browser. The WWW server takes charge of conferencing management including the information related to the participants and provides supported conference tools such as whiteboard, chatting and multimedia controls. Therefore the participants can easily join the conference sessions and perform conference working regardless of network connection situations. We used the Java to implement the seamless session connections and interaction between the conference participants which are the most important when implementing the video conferencing system on the WWW and used the ActiveX technology about the audio and video controls to make it easy the hardware control.

• Proceedings of the Korean Society of Medical Physics Conference
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• 2002.09a
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• pp.457-460
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• 2002

The image quality of three-dimensional (3D) images has been widely investigated by the qualitative analysis method. A need remains for an objective and quantitative method to assess the image quality of 3D volume-rendered images. The purpose of this study was to evaluate the quantitative accuracy of distance measurements on 3D volume-rendered images of a dry human skull by using multi-detector computed tomography (MDCT). A radiologist measured five times the twenty-one direct measurement line items composed among twelve reference points on the skull surface with a digital vernier caliper. The water filled skull specimen was scanned with a MDCT according to the section thicknesses of 1.25, 2.50, 3.75, and 5.00 mm for helical (high quality; pitch 3:1) scan mode. MDCT data were reconstructed with its acquisition section thickness and with 1.25 mm section thickness for all scans. An observer also measured seven times the corresponding items on 3D volume-rendered images with measuring tools provided by volumetric analysis software. The quantitative accuracy of distance measurements on the 3D volume-rendered images was statistically evaluated (p-value < 0.05) by comparatively analyzing these measurements with the direct distance measurements. The accuracy of distance measurements on the 3D volume-rendered MDCT images acquired with 1.25, 2.50, 3,75 and 5.00 mm section thickness and reconstructed with its section thickness were 48%, 33%, 23%, and 14%, respectively. Meanwhile, there were insignificant statistical differences in accuracy of distance measurements among 3D volume-rendered images reconstructed with 1.25 mm section thickness for the each acquisition section thickness. MDCT images acquired with thick section thickness and reconstructed with thin section thickness in helical scan mode should be effectively used in medical planning of 3D volume-rendered images. The quantitative analysis of distance measurement may be a useful tool for evaluating the quantitative accuracy and the defining optimal parameters of 3D volume-rendered CT images.

• 한국지구물리탐사학회:학술대회논문집
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• 2004.08a
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• pp.157-179
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• 2004

The application of magnetic method for archaeoprospection has been carried out through two archaeological areas in Egypt, Abydos and Abu Sir, In order to find out tile ancient Egyptian archaeological features. The magnetic work at the selected archaeological site of Abydos area was carried out by gradiometer survey, while magnetic work at the selected archaeological site of Abu Sir area was carried out by gradiometer survey and magnetic susceptibility measurements. A gradiometer survey with raster of 0.5 m/0.5 m has been carried out on a surface area of $9600 m^2$ at Abydos area to relocate the buried Solar Boats. The magnetic data were processed using Geoplot software to treat the field noises and enhance the quality of the obtained images. The final magnetic images indicate the existence of 12 Solar Boats as well as tombs, remains of ancient rooms and walls. All of them are expected to belong to the Middle Kingdom, particularly from the 18th to 20th Dynasties. Two magnetic tools have been applied over a selected site of $25600 m^2$ at Abu Sir area in order to detect the hidden archaeological features nearby the Sun Temple. The acquisition of the magnetic data was initiated by the measurements of the topsoil magnetic susceptibility of 272 samples collected from the whole studied area, and then followed by the gradiometer survey to measure tile vertical gradient of the geomagnetic field over an area of $14400 m^2$. The magnetic susceptibility results show the presence of high concentration at the middle part of the study area with a little extension to the south western side, with maximum value of about $36{\times}10^5$ SI. They may indicate the proximity of ritual monuments. Also, they offered the site of interest for carrying out a gradiometer survey. The gradiometer results show tile existence of numerous distributed archaeological features made of mud-bricks with different shapes and sizes. They may indicate tombs, burial rooms, dissected walls; all of them are expected to belong to the 5th Dynasty of pharaohs, who used to build their buildings by mud bricks. The depth of the expected buried archaeological features has been estimated from tihe gradiometer. It is around 1.2m for deep features and 0.42 m for shallow features.

• Korean Journal of Remote Sensing
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• v.35 no.6_4
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• pp.1327-1339
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• 2019

Surface reflectance obtained by absolute atmospheric correction from satellite images is useful for scientific land applications and analysis ready data (ARD). For Landsat and Sentinel-2 images, many types of radiometric processing methods have been developed, and these images are supported by most commercial and open-source software. However, in the case of KOMPSAT 3/3A images, there are currently no tools or open source resources for obtaining the reflectance at the top-of-atmosphere (TOA) and top-of-canopy (TOC). In this study, the atmospheric correction module of KOMPSAT 3/3A images is newly implemented to the optical calibration algorithm supported in the Orfeo ToolBox (OTB), a remote sensing open-source tool. This module contains the sensor model and spectral response data of KOMPSAT 3A. Aerosol measurement properties, such as AERONET data, can be used to generate TOC reflectance image. Using this module, an experiment was conducted, and the reflection products for TOA and TOC with and without AERONET data were obtained. This approach can be used for building the ARD database for surface reflection by absolute atmospheric correction derived from KOMPSAT 3/3A satellite images.

• Communications of Mathematical Education
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• v.29 no.1
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• pp.35-49
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• 2015

3D-Printing is one of the most innovative technologies that will be widely used in the 21st century. 3D-Printing also serves as an indispensable tool in STEAM education. In this article, we introduce what we have done in our mathematical modeling class in Uni. and recent R&E project under the support of Korean Foundation for the Advancement of Science and Creativity. We planned a model of STEAM education originating from our wish to make tangible models that use mathematical formulas to express the natural beauty of an object. We used a free, open-source software, Sage, to simulate these models online. Then, we created a program that generates a .STL file from these 3D images. This model can help students understand the natural beauty inherent in mathematics and use formulas and technology tools to simulate models in 3D. Finally, we were able to help students to create their own. STL files through a website we developed by adding Sage code into a Sage notebook. Then students can make and hold a 3D object of their very own. This process shows the possibility that mathematics, art and 3D-Printing can be effectively used to achieve the goals of STEAM education.

• Journal of KIISE:Software and Applications
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• v.32 no.12
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• pp.1217-1228
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• 2005

Recently, since DNA computing has been widely studied for various applications, DNA sequence design which is the most basic and important step for DNA computing has been highlighted. In previous works, DNA sequence design has been formulated as a multi-objective optimization task, and solved by elitist non-dominated sorting genetic algorithm (NSGA-II). However, NSGA-II needed lots of computational time. Therefore, we use an $\varepsilon$- multiobjective evolutionarv algorithm ($\varepsilon$-MOEA) to overcome the drawbacks of NSGA-II in this paper. To compare the performance of two algorithms in detail, we apply both algorithms to the DTLZ2 benchmark function. $\varepsilon$-MOEA outperformed NSGA-II in both convergence and diversity, $70\%$ and $73\%$ respectively. Especially, $\varepsilon$-MOEA finds optimal solutions using small computational time. Based on these results, we redesign the DNA sequences generated by the previous DNA sequence design tools and the DNA sequences for the 7-travelling salesman problem (TSP). The experimental results show that $\varepsilon$-MOEA outperforms the most cases. Especially, for 7-TSP, $\varepsilon$-MOEA achieves the comparative results two tines faster while finding $22\%$ improved diversity and $92\%$ improved convergence in final solutions using the same time.

• Journal of Biosystems Engineering
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• v.43 no.3
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• pp.247-254
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• 2018

Purpose: Although previous studies have performed on-farm evaluations for the control of airborne diseases such as foot-and-mouth disease (FMD) and influenza, disease control during the process of livestock and manure transportation has not been investigated thoroughly. The objective of this study is to predict common patterns of livestock-vehicle movement. Methods: Global positioning system (GPS) data collected during 2012 and 2013 from livestock vehicles on Jeju Island, South Korea, were analyzed. The GPS data included the coordinates of moving vehicles according to the time and date as well as the locations of livestock farms and manure-keeping sites. Data from 2012 were added to Esri software ArcGIS 10.1 and two approaches were adopted for predicting common vehicle-movement patterns, i.e., point-density and Euclidean-distance tools. To compare the predicted patterns with actual patterns for 2013, the same analysis was performed on the actual data. Results: When the manure-keeping sites and livestock farms were the same in both years, the common patterns of 2012 and 2013 were similar; however, differences arose in the patterns when these sites were changed. By using the point-density tool and Euclidean-distance tool, the average similarity between the predicted and actual common patterns for the three vehicles was 80% and 72%, respectively. Conclusions: From this analysis, we can determine common patterns of livestock vehicles using previous year's data. In the future, to obtain more accurate results and to devise a model for predicting patterns of vehicle movement, more dependent and independent variables will be considered.

• Journal of Digital Convergence
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• v.14 no.4
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• pp.419-424
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• 2016

In this paper, we studied a light distribution for the LED chips arrangement using an optical design software. The structures of the edge type LED luminaires are reflector plane, LGP(lighting guide plane) and diffuse plane. The reflector plane is on the middle of the overall structure. We had simulation that placing LED chips on the reflector center of the reflector edge by changing the position of LED chips above the reflector center at 1mm, 2mm, and 3mm respectively. In the case, when LED chips are on the center of the reflector, it shows the light distribution of the general diffuse illumination, the semi-direct distribution with 0.56 efficiency and the direct distribution with 0.31 efficiency. And the wedge type LGP shows more efficiency than the flat type. Gradually increasing shape of semi-spherical type by 0.015mm has power of 1.02W, efficiency of 0.25, and maximum luminous intensity of 0.104W/sr, it also and shows the better optical characteristics than the reflector plane that have no patterns. This semi-spherical type shows the better optical characteristics than the reflector plane that have no patterns.

• The Journal of the Korea Contents Association
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• v.20 no.1
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• pp.630-643
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• 2020

Recently, consumers have changed their role to consumers and producers who make what they want. The way clothes are produced is also needed to change according to modern consumption methods. Knitting Machine was one of them, and although it was a mass-produced device, it developed a device that could make clothes anywhere on a small production craze. Knit-making requires more consideration than other clothing designs, which requires consideration of users' web usability. Therefore, this study proposes an assessment tool that can evaluate web usability of clothing-making sites using knitting machines. To this end, the examples of the Knitting Machine program and custom product production websites and the each UI were investigated and analyzed. Based on these prior surveys, the draft evaluation items were drawn, and three Delphi surveys were conducted on the basis of the draft to produce assessment tools after classifying, modifying and deleting items. Through this study, we look forward to improving the usability of the customized product-making website of Knitting Machine in the future and popularizing the Knitting Machine.

• Journal of the Korea institute for structural maintenance and inspection
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• v.17 no.2
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• pp.1-9
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• 2013

In recent years, numerous mega-size and complex civil infrastructures have been constructed worldwide. For the more precise construction and maintenance process management of these civil infrastructures, the application of a variety of smart sensor-based structural health monitoring (SHM) systems is required. The efficient management of both sensors and collected databases is also very important. Recently, several kinds of database access technologies using Quick Response (QR) code and Augmented Reality (AR) applications have been developed. These technologies provide software tools incorporated with mobile devices, such as smart phone, tablet PC and smart pad systems, so that databases can be accessed very quickly and easily. In this paper, an AR-based structural health monitoring technique is suggested for sensor management and the efficient access of databases collected from sensor networks that are distributed at target structures. The global positioning system (GPS) in mobile devices simultaneously recognizes the user location and sensor location, and calculates the distance between the two locations. In addition, the processed health monitoring results are sent from a main server to the user's mobile device, via the RSS (really simple syndication) feed format. It can be confirmed that the AR-based structural health monitoring technique is very useful for the real-time construction process management of numerous mega-size and complex civil infrastructures.