• Journal of Korean Society for Geospatial Information Science
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• v.22 no.4
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• pp.3-11
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• 2014

Recently, rapid urbanization has necessitated continuous updates in digital map to provide the latest and accurate information for users. However, conventional aerial photogrammetry has some restrictions on periodic updates of small areas due to high cost, and as-built drawing also brings some problems with maintaining quality. Alternatively, this paper proposes a scheme for efficient and accurate update of digital map using point cloud data acquired by Terrestrial Laser Scanner (TLS). Initially, from the whole point cloud data, the building sides are extracted and projected onto a 2D image to trace out the 2D building footprints. In order to register the footprint extractions on the digital map, 2D Affine model is used. For Affine parameter estimation, the centroids of each footprint groups are randomly chosen and matched by means of a modified RANSAC algorithm. Based on proposed algorithm, the experimental results showed that it is possible to renew digital map using building footprint extracted from TLS data.

• Journal of the Microelectronics and Packaging Society
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• v.24 no.4
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• pp.59-63
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• 2017

The n-type GaN semiconductor has excellent properties as a photoelectrode, but it has disadvantage that its reliability is deteriorated due to the photocorrosion because the oxygen reaction occurs on the surface. For this reason, there are fundamental attempts to avoid photocorrosion reaction of GaN surfaces by using the p-type GaN as a photoelectrode where hydrogen generation reaction occurs on the surface. However, p-type GaN has a problem of low efficiency because of its high resistivity and low hole mobility. In this study, we try to improve the photocurrent efficiency by activation process for the p-type GaN. The p-type GaN was annealed for 1 min. at $500^{\circ}C$ in $N_2$ atmosphere. Hall effect measurement system was used for the electrical properties and potentiostat (PARSTAT4000) was used to measure the photoelectrochemical (PEC) characteristics. Consequently, the photocurrent density was improved more than 1.5 times by improving the activation process for the p-type GaN. Also, its reliability was maintained for 3 hours.

• Journal of the Korea Society for Simulation
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• v.26 no.4
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• pp.23-34
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• 2017

During Khmer Rouge Regime, Cambodian pop music was completely forgotten since 90% of artists were killed. After recovering from war since 1979, the music started to grow again in 1990. However, Cambodian popular music dynamic and flows are observably directed by the multifaceted socioeconomic, political and creative forces. The major problems are the plagiarism and piracy which have been prevailing for years in the industry. Recently, the consciousness of the need to preserve Khmer original songs from both fans and artist have been increased and become a new trend for Cambodia young population. Still, the music quality is in the limit state. To increase the mind-set, the feedbacks and inspiration are needed. The study suggested a music ranking website using sentiment analysis which data were collected from Production Companies Facebook Pages' posts and comments. The study proposed an algorithm which translates from Khmer to English, doing sentiment analysis and generate the ranking. The result showed 80% accuracy of translation and sentiment analysis on the proposed system. The songs that rank high in the system are the songs which are original and fit the occasion in Cambodia. With the proposed ranking algorithm, it would help to increase the competitive advantage of the musical productions as well as to encourage the producers to compose the new songs which fit the particular activities and event.

• Journal of Korea Society of Industrial Information Systems
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• v.18 no.4
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• pp.1-8
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• 2013

In the modern society, instructional methods using diverse media have appeared thanks to the development of Information & Communication Technology, and applicability of such instructional methods has been fully corroborated. However, customized contents allowing for disabled children's environment are still insufficient. Hence, this study produced educational contents of play activities for children with developmental disability, through applying N-screen technology, IT technology that can provide the same contents via a variety of digital media. The produced contents allow programs to be set up according to a child's individual characteristics and be carried out anywhere and anytime via an Internet-enabled digital device. Further, the developed contents were produced so that they could be accessed from a child's various environment (home, school, etc.) via a PC, a smart phone, a portable from a child's various environment (home, school, etc.) via a PC, a smart phone, a portable device, etc. and that the same educational program could be conducted in linkage at home, school, etc. Three children with Intellectual disability and autism spectrum disorder were applied to the manufactured content. As a result, Content interaction between interaction between teachers and students in play training could use as a medium.In addition, the children's ability to select the appropriate components and reinforcements, special education professionals have used the content of the interviews are helpful in mediation than the existing content.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.2
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• pp.97-104
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• 2018

Recently, many studies have examined UAVs (unmanned aerial vehicles), which can replace and supplement existing surveying sensors, systems, and images. This study focused on the use of UAV images and assessed the possibility of utilization in areas where it is difficult to obtain GCPs (ground control points), such as disasters. Therefore, 3D (dimensional) pointcloud data were generated using UAV images and the absolute/relative accuracy of the generated model data using GCPs and without GCPs was assessed. The results showed the 3D shape pointcloud generated by UAV image matching was proven if the relative accuracy was set, regardless of whether GCPs were used or not; the quantitative measurement error rate was within 1%. Even if the absolute accuracy was low, the 3D shape pointcloud that had been post processed quickly was sufficient to be utilized when it is impossible to acquire GCPs or urgent analysis is required. In particular, the results can obtain quantitative measurements and meaningful data, such as the length and area, even in cases with the ground reference point surveying and post-process.

• The Journal of Society for e-Business Studies
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• v.23 no.2
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• pp.21-31
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• 2018

Korean banknotes are similar in size, and their braille tend to worn out as they get old. These characteristics of Korean banknotes make the blind people, who mainly rely on the braille, even harder to distinguish the banknotes. Not only that, this can even lead to economic loss. There are already existing systems for recognizing the banknotes, but they don't support Korean banknotes. Furthermore, because they are developed as a mobile application, it is not easy for the blind people to use the system. Therefore, in this paper, we develop a Raspberry Pi-based banknote recognition system that not only recognizes the Korean banknotes but also are easily accessible by the blind people. Our system starts recognition with a very simple action of the user, and the blind people can hear the recognition results by sound. In order to choose the best feature extraction algorithm that directly affects the performance of the system, we compare the performance of SIFT, SURF, and ORB, which are representative feature extraction algorithms at present, in real environments. Through experiments in various real environments, we adopted SIFT to implement our system, which showed the highest accuracy of 95%.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.16 no.5
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• pp.137-142
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• 2016

A two-step open system(TOS) was proposed to relay between a healing platform and a repository of personal health documents. TOS was designed by taking into consideration the pubsub service based on large scale connections to monitor a provider's access/request process for health documents in real time. TOS, however, uses WebSocket as a communication protocol in case of pubsub. Given the operational environment of low quality wireless networks for mobile devices that are user terminals in a healing platform, there is a need to add a messaging protocol to support QoS as well as a transmission protocol. As a light messaging protocol optimized for mobile devices, MQTT defines reliable messaging QoS to consider a wireless network situation of low speed/low quality. This study designed an MQTT protocol-based message broker to support QoS in case of large scale connections and pubsub by taking into consideration mobile devices that are user terminals in a healing platform. After designing a model between TOS and MQTT message broker, the study implemented a prototype based on the proposed design and compared it with its counterparts from previous studies based on the performance indicators in a load-test with the MQTT client tool.

• Journal of Advanced Marine Engineering and Technology
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• v.39 no.1
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• pp.86-93
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• 2015

Recently, the development of Maritime Service Portfolios (MSPs) for the safe navigation of ship has been discussed internationally. For the successful service of the MSPs, first of all, studies for the standardization about the structure and data structure of MSPs should be preceded. Also, it is necessary to evaluate and assess whether the services are effective for safe navigation, and provided data and portrayal methods are proper. However, because great dangers will be accompanied when untested MSPs about their effectiveness and safety are applied in real ship navigation, it is necessary that effectiveness and safety of the MSPs should be proven under various navigational conditions and environments by simulation. In this paper, we propose a 3D navigation simulation system using desktop PC environment, which is proper for evaluating the effectiveness of MSPs. The system consists of three modules which are simulation scenario editor, 3D visualization of navigational environment and 2D navigational equipment. The scenario editor module provides an environment setting for simulation, such as properties, routes and positions of vessels and aids to navigations. It also provides functions to create a scenario for the simulation to operate. Additionally, the 3D visualization module provides 3D navigational environment which shows interplay between geographical and navigational environment based on the created scenario. The 2D navigational equipment module provides visualization functions of various navigational equipment, shows the interaction between ship's navigational equipment and ship's environment. The simulation scenario, in which various kinds of ships are routing in the port, is created by the developed simulation system, and experimented whether this developed system is appropriate to evaluate and assess the MSPs developed by the International Maritime Organization.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.14 no.6
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• pp.69-76
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• 2015

Although traffic information has been actively analyzed using big data, it has not been used as much with the consideration of driver characteristics. Among the various types of information, road signs can directly affect the driver. Road signs must provide the optimal information that enables drivers to reach their destinations with ease as well as information suitable for navigation systems. However, present road sign rules provide standardized information, regardless of the road type or size. This study suggests a method for providing road information that will help drivers determine their behavior. First, the minimum character size that can be used on a road sign for each design speed was obtained with respect to the visibility and decipherability of a road sign. Instead of conventional diagram-based direction guidance, a scenario using split-based direction guidance was created. To verify the effectiveness of the provided information, a three-dimensional simulated road environment was constructed, and a driving simulator was used for the test. At a simple plane intersection, the driver was not greatly influenced by directional guidance, but at a complex, three-dimensional intersection, the driver preferred summary-based directional guidance, which is instinctive guidance, over diagram-based guidance. On the basis of the test results, a secondary verification test that applied split-based guidance at a three-dimensional intersection confirmed that the driver had no problems in making decisions.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.20 no.4
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• pp.187-193
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• 2020

In this study, we wanted to analyze the factors at the national university level that affect college students ' elimination. In addition, national universities, private universities, universities in Seoul and universities outside of Seoul were divided into more college-specific characteristics. Except for leave of absence and departure from school, it was defined as a middle school dropout among changes of students. The data were used for analysis by receiving raw data from "University Alerts," which are operated by the Ministry of Education and the Korean Council for Educational Universities. At the university notification, 222 universities out of the schools classified as "Universities" were utilized for final analysis, and jobs, credits, scholarships, tuition fees, students, independent students, and full-time teachers were secured through multiple education. Overall, the higher the average graduate level and employee-rate the lower the rate of elimination from the middle of college students, the analysis showed. Second, the higher the average tuition fees at private universities, the more negatively affects the rate of elimination of university students. Third, higher tuition fees at universities outside the Seoul metropolitan area have a negative impact on the rate of elimination of students.