• Korean Journal of Remote Sensing
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• v.36 no.2_2
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• pp.365-377
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• 2020

Continuous monitoring and immediate response is essential to protect the national maritime territory and maritime resources from the activities of illegal ships. Synthetic Aperture Radar (SAR) images with a wide range of images are effective for maritime surveillance asthe weather and day-night conditions rarely affect to image acquisition. However, an effective ship detection is not easy due to the huge data size of SAR images and various characteristics such as the speckle noise. In this study, the Human Visual Attention System (HVAS) algorithm was applied to KOMPSAT-5 to extract the initial targets, and the SAR-Split algorithm depending on the imaging modes was used to remove false alarms. The detected targets were finally selected by the Constant False Alarm Rate (CFAR) algorithm and matched with the ship's Automatic Identification System (AIS) information. Overall, the detected targets were well matched with AIS data, but some false alarms by ship wakes were observed. The detection rate was about 80% in ES mode and about 64% in ST mode. It is expected that the developed ship detection algorithm will contribute to the construction of a wide area maritime surveillance network.

• Land and Housing Review
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• v.9 no.2
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• pp.9-19
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• 2018

The purpose of the study is to show the possibility of the enlargement of land banking types through employment of the French land bank case. For sustainable urban regeneration projects, it is necessary to improve the land banking system with comprehensive land banking types. There are a total of 35 land banking agencies in France, which are made according to the needs of the municipality. The main function of these institutions is to perform functions such as land acquisition, management, division, land maintenance(decontamination, etc.), land use plan review and so on. In the 1960s and 1970s, mainly purchase and maintenance of land mainly focused on Brownfield and idle land, but since 2000 the land purchase business is mainly for the supply of social rental housing which is missing It was. The use of land banks is most frequently mentioned as a way of how to supply land at a low price in urban renewal projects. To that end, it is necessary to revise related laws, even if the law is revised so that land for urban regeneration projects can be secured, due to the limit of financial resources, land for the urban regeneration project nationwide secured It will not be easy without policy judgment of a positive nation. Therefore, securing land reserve resources for urban regeneration projects utilizing residential district funds and municipal maintenance funds is essential. In addition, even on a small scale, it is necessary to consider the banking of land for regional capitalization at the local government level.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.27 no.5
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• pp.619-628
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• 2009

LiDAR has capability of rapid data acquisition and provides useful information for reconstructing surface of the Earth. However, Extracting information from LiDAR data is not easy task because LiDAR data consist of irregularly distributed point clouds of 3D coordinates and lack of semantic and visual information. This thesis proposed methods for automatic extraction of buildings and 3D detail modeling using airborne LiDAR data. As for preprocessing, noise and unnecessary data were removed by iterative surface fitting and then classification of ground and non-ground data was performed by analyzing histogram. Footprints of the buildings were extracted by tracing points on the building boundaries. The refined footprints were obtained by regularization based on the building hypothesis. The accuracy of building footprints were evaluated by comparing with 1:1,000 digital vector maps. The horizontal RMSE was 0.56m for test areas. Finally, a method of 3D modeling of roof superstructure was developed. Statistical and geometric information of the LiDAR data on building roof were analyzed to segment data and to determine roof shape. The superstructures on the roof were modeled by 3D analytical functions that were derived by least square method. The accuracy of the 3D modeling was estimated using simulation data. The RMSEs were 0.91m, 1.43m, 1.85m and 1.97m for flat, sloped, arch and dome shapes, respectively. The methods developed in study show that the automation of 3D building modeling process was effectively performed.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.11 no.5
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• pp.1838-1844
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• 2010

In distance education, contents are to convey what to learn to learners, and the efficient quality assurance of contents is the very first step to the enhancement of distance education. Most studies of the quality assurance of contents have mostly centered around the development of evaluation tools, and few studies have ever focused on analysis of the quality of contents itself, since it's not easy to do that due to difficulties in the selection of evaluatees or of contents to be analyzed. The purpose of this study was to analyze the quality of 58 distance education contents of on-the-job training and another training for the acquisition of qualifications. As a result, the contents of the learning contents segment ranked first. Among the components of each segment, there was room for improvement in the level of learning and learning elements in the learning contents segment. In terms of instructional design, the quality of interaction components should be taken to another level to boost the quality of contents in this segment. The findings of the study are expected to give some suggestions about which parts of contents should be improved in quality from a perspective of contents developers or suppliers to enhance the overall quality of contents.

• Journal of the Korean Institute of Intelligent Systems
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• v.22 no.2
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• pp.218-224
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• 2012

Recently, as the needs of developing the micro autonomous underwater vehicle (AUV) are increasing, the acquisition of the elementary technology is urgent. While they mostly utilizes information of the forward looking sonar (FLS) in conventional studies of the local path control as an elementary technology, it is desirable to use the obstacle avoidance sonar (OAS) because the size of the FLS is not suitable for the micro AUV. In brief, the local path control system based on the OAS for the micro AUV operates with the following problems: the OAS offers low bearing resolution and local range information, it requires the system that has reduced power consumption to extend the mission execution time, and it requires an easy design procedure in terms of its structures and parameters. To solve these problems, an intelligent local path control algorithm based on the beam modeling of OAS with the evolution strategy (ES) and the fuzzy logic controller (FLC), is proposed. To verify the performance and analyze the characteristic of the proposed algorithm, the course control of the underwater flight vehicle (UFV) is performed in the horizontal plane. Simulation results show that the feasibility of real application and the necessity of additional work in the proposed algorithm.

• Journal of The Korean Association of Information Education
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• v.23 no.6
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• pp.675-687
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• 2019

As interest in artificial intelligence increases, each university has been establishing a special graduate school with artificial intelligence major, and recently, the Korea government has established various support policies for artificial intelligence education. However, each university has a lot of difficulties because it has little experience in operating graduate education with the latest field of artificial intelligence and it is not easy to find experts. In this study, the response of graduate school students majoring in artificial intelligence was analyzed using IPA technique, and the direction of education of graduate school artificial intelligence major was searched. Among the 40 items surveyed by IPA, 12 items such as systematization of artificial intelligence curriculum, progress of class considering learning level, improvement of academic relations with guidance professors were extracted as items to be improved first. On the other hand, 8 items such as assistant capacity, and relationship with colleagues were overloaded, and twelve items such as instructor's lecture competency, appropriateness of educational contents, learner's artificial intelligence skills and knowledge, and attitude acquisition were to be maintained. In addition, eight items such as convergence education curriculum and diversity of education methods were all low in importance and performance. It is suggested that AI graduate school should be divided into two tracks(technical specialization, convergence expansion) by educational goal, and each track should be conducted by level-specific educational contents and methods suitable for student level. The curriculum should be elaborate and systematic to acquire AI knowledge, skills, and attitudes, and should have an individualized guidance system centered on excellent faculty members.

• Geophysics and Geophysical Exploration
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• v.15 no.1
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• pp.33-38
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• 2012

A resistivity method has been applied to wide range of engineering and environmental problems with the help of automatic and precise data acquisition. Thus, more accurate modeling and inversion of time-lapse monitoring data are required since resistivity monitoring has been introduced to quantitatively find out subsurface changes With respect to time. Here, we used the finite element method (FEM) for 3D resistivity modeling since the method is easy to realize complex topography and arbitrary shaped anomalous bodies. In the FEM, the linear elements, also referred to as first order elements, have certain advantages of simple formulation and narrow bandwidth of system equation. However, the linear elements show the poor accuracy and slow convergence of the solution with respect to the number of elements or nodes. To achieve the higher accuracy of finite element solution, high order elements are generally used. In this study, we developed a 3D resistivity modeling program using high order Serendipity elements. Comparing the Serendipity element solutions for a cube model with the linear element solutions, we assured that the Serendipity element solutions are more accurate than the linear element solutions in the 3D resistivity modeling.

• Journal of the Korean Institute of Intelligent Systems
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• v.25 no.2
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• pp.174-179
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• 2015

Failure Mode and Effects Analysis (FMEA) has been used by Dynamic Positioning (DP) system for risk and reliability analysis. However, there are limitations associated with its implementation in offshore project. 1) since the failure data measured from the SCADA system is missing or unreliable, assessments of Severity, Occurrence, Detection are based on expert's knowledge; 2) it is not easy for experts to precisely evaluate the three risk factors. The risk factors are often expressed in a linguistic way. 3) the relative importance among three risk factors are rarely even considered. To solve these problems and improve the effectiveness of the traditional FMEA, we suggest a Fuzzy-FMEA method for risk and failure mode analysis in Dynamic Positioning System of offshore. The information gathered from DP FMEA report and DP FMEA Proving Trials is expressed using fuzzy linguistic terms. The proposed method is applied to an offshore Dynamic Positioning system, and the results are compared with traditional FMEA.

• Korean Journal of Applied Biomechanics
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• v.24 no.2
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• pp.181-187
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• 2014

In this study, a real-time evaluation system for quantitative dynamic fitting during pedaling was developed. The system is consisted of LED markers, a digital camera connected to a computer and a marker detecting program. LED markers are attached to hip, knee, ankle joint and fifth metatarsal in the sagittal plane. Playstation3 eye which is selected as a main digital camera in this paper has many merits for using motion capture, such as high FPS (Frame per second) about 180FPS, $320{\times}240$ resolution, and low-cost with easy to use. The maker detecting program was made by using Labview2010 with Vision builder. The program was made up of three parts, image acquisition & processing, marker detection & joint angle calculation, and output section. The digital camera's image was acquired in 95FPS, and the program was set-up to measure the lower-joint angle in real-time, providing the user as a graph, and allowing to save it as a test file. The system was verified by pedalling at three saddle heights (knee angle: 25, 35, $45^{\circ}$) and three cadences (30, 60, 90 rpm) at each saddle heights by using Holmes method, a method of measuring lower limbs angle, to determine the saddle height. The result has shown low average error and strong correlation of the system, respectively, $1.18{\pm}0.44^{\circ}$, $0.99{\pm}0.01^{\circ}$. There was little error due to the changes in the saddle height but absolute error occurred by cadence. Considering the average error is approximately $1^{\circ}$, it is a suitable system for quantitative dynamic fitting evaluation. It is necessary to decrease error by using two digital camera with frontal and sagittal plane in future study.

• Journal of Korean language education
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• v.29 no.1
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• pp.1-23
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• 2018

This paper investigates how adult Mandarin- and English- speaking learners of Korean perceive Korean vowels, with focus on the effect of the first language (L1) and the second language (L2) acoustic relationship, as well as the influence of Korean language experience. For this study, native Mandarin and Canadian English speakers who have learned Korean as a foreign language, as well as a control group of native Korean speakers, participated in two experiments. Experiment 1 was designed to examine acoustic similarities between Korean and English vowels, as well as Korean and Mandarin vowels to predict which Korean vowels are relatively easy, or difficult for L2 learners to perceive. The linear discriminant analysis (Klecka, 1980) based on their L1-L2 acoustic similarity predicted that L2 Mandarin learners would have perceptual difficulty rankings for Korean vowels as follows: (the easiest) /i, a, e/ >> /ɨ, ʌ, o, u/ (most difficult), whereas L2 English learners would have perceptual difficulty rankings for Korean vowels as follows: (the easiest) /i, a, e, ɨ, ʌ/ >> /o, u/ (most difficult). The goal of Experiment 2 was to test how accurately L2 Mandarin and English learners perceive Korean vowels /ɨ, ʌ, o, u/ which are considered to be difficult for L2 learners. The results of a mixed-effects logistic model revealed that English listeners showed higher identification accuracy for Korean vowels than Mandarin listeners, indicating that having a larger L1 vowel inventory than the L2 facilitates L2 vowel perception. However, both groups have the same ranking of Korean vowel perceptual difficulty: ɨ > ʌ > u > o. This finding indicates that adult learners of Korean can perceive the new vowel /ɨ/, which does not exist in their L1, more accurately than the vowel /o/, which is acoustically similar to vowels in their L1, suggesting that L2 learners are more likely to establish additional phonetic categories for new vowels. In terms of the influence of experience with L2, it was found that identification accuracy increases as Korean language experience rises. In other words, the more experienced English and Mandarin learners of Korean are, the more likely they are to have better identification accuracy in Korean vowels than less experienced learners of Korean. Moreover, there is no interaction between L1 background and L2 experience, showing that identification accuracy of Korean vowels is higher as Korean language experience increases regardless of their L1 background. Overall, these findings of the two experiments demonstrated that acoustic similarity between L1 and L2 sounds using the LDA model can partially predict perceptual difficulty in L2 acquisition, indicating that other factors such as perceptual similarity between L1 and L2, the merge of Korean /o/ and /u/ may also influence their Korean vowel perception.