• Proceedings of the Korean Information Science Society Conference
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• 2003.04a
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• pp.566-568
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• 2003

본 논문에서는 SCORM을 기반으로 한 e-Learning 시스템에서 학습자의 학습 활동을 트래킹하여 학습자의 수준을 적응적으로 판단하는 기법을 제시하였다. 제시된 기법에서는 모집단의 크기가 작을 경우 교수자가 지정한 난이도를 이용하여 학습자의 수준을 판단하고, 모집단의 크기가 충분히 클 경우에는 문항반응이론을 적응한 난이도에 의해 학습자의 수준을 판단하였다. 문항반옹이론을 적용할 시점에서 교수자가 지정한 난이도가 문항반응이론에서 추정한 난이도와 차이가 날 경우, 교수자가 지정한 난이도를 문항반응이론의 난이도로 수정하는 적응적인 기법을 제시하였다. SCORM의 트래킹 기능을 이용하여 실험한 결과 문제를 푼 학습자의 수가 적을 경우에는 학습자 수의 변화에 따라 학습자의 수준이 계속 바뀌는 문제점이 있음을 알 수 있었다. 따라서 모집단의 크기가 작을 경우, 본 논문에서 제안한 방법에 의해 교수자가 지정한 문항의 난이도를 이용하여 학습자의 수준을 판단하는 것이 효과적이었다.

• Proceedings of the Korean Information Science Society Conference
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• 2012.06c
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• pp.335-337
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• 2012

전투공간 시뮬레이션 결과를 가시화할 뿐 아니라 시나리오 가시화 중에 사용자가 선택한 엔티티의 상세한 관찰을 제공하기 위해 스테레오 3D 모델 뷰어를 개발하여 가시화 시스템의 프로토타입을 구성하였다. 전투공간 가시화를 위해서는 가시화 스프트웨어인 SIMDIS를 사용하였다. 사용자는 시뮬레이션 가시화 스크린 상에서 엔티티를 선택할 수 있으며, 이 엔티티의 자세한 관찰은 스테레오 3D 모델 뷰어에 가시화 된다. 모델 뷰어는 사용자에게 엔티티 관찰 시 몰입감과 인지도를 향상시키기 위하여 헤드 트래킹 기술을 적용하였다. 사용자의 위치를 추적하기 위해서는 깊이 카메라를 이용하였으며, 획득한 깊이 영상을 통해 실시간 사용자 헤드 트래킹을 적용하였다. 구현된 시스템은 SIMDIS를 이용한 전투공간 시뮬레이션 가시화와 스테레오 3D 뷰어를 각각 가시화하기 위하여 2D 디스플레이와 3D TV를 사용하였다.

• Proceedings of the Korea Institute of Convergence Signal Processing
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• 2000.08a
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• pp.229-232
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• 2000

문자인식은 멀티 모달 인터페이스의 핵심요소로서 이동 환경에서 사용자의 다양한 요구사항을 처리하는 지능형 단말기의 구현을 위해 필수적으로 개발되어야 할 과제이다. 그러나 대부분의 기존 연구는 인식률의 향상만을 위해서 복잡한 획 해석과 백트래킹을 사용하기 때문에 멀티미디어 단말기에 적합하지 못하다. 따라서 본 논문은 멀티미디어 단말기로의 적용을 목적으로 한 새로운 온라인 한글 문자 인식 방법을 제안한다. 제안된 방법은 한글 문자의 특성정보와 획 정보를 기반으로 구축된 한글 데이터 베이스를 사용한다. 또한 획간의 위치관계를 이용한 순차적 자소 분리와 향상된 백트래킹 기법에 의해서 보다 빠른 처리 시간을 보장한다. 제안된 시스템의 성능 평가는 상용 1,200 단어를 이용하여 다수의 필기자가 필기한 한글 600문자를 대상으로 실험한 결과 95% 이상의 인식률을 얻었다.

• Fire Science and Engineering
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• v.31 no.1
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• pp.42-49
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• 2017

The present article reports the tracking characteristics of phenolic resin insulation material due to accelerated degradation. For assessing insulation degradation of the phenolic resin insulation material, experiment samples with equivalent years of 0, 10, 20, 30, and 40 years were produced by conducting accelerated degradation experiments using Arrhenius equation. Subsequently, tracking experiments according to KS C IEC 60112 standard were conducted for the experiment samples that were previously subjected to accelerated degradation. According to the measured results for tracking characteristics of phenolic resin subjected to accelerated degradation, upon dropping of 0.1% ammonium chloride, the risks were shown to increase by 1.38 times for the equivalent life of 10 years; 1.45 times for 20 years; 1.62 times for 30 years; and 1.94 times for 40 years based on the equivalent life of 0 year. Upon dropping of 0.01% ammonium chloride, the risks were shown to increase by 1.39 times for the equivalent life of 10 years; 1.52 times for 20 years; 1.99 times for 30 years; and 5.30 times for 40 years. According to the experimental results, the tracking risk was shown to be higher for longer-duration insulation degradation due to aging. In particular, the risk was observed to be greatly increased in the case of the equivalent life of 40 years. Therefore, it is proposed that the occurrence possibility and the risk of electric fires could be minimized through institutional preparation of recommended replacement period by considering risks such as insulation degradation, etc. due to aging.

• Korean Journal of Remote Sensing
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• v.34 no.3
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• pp.495-506
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• 2018

Global interest in climate change and sea level rise has led to active research on the velocities of glaciers. In studies about the velocity of glaciers, in-situ measurements can obtain the most accurate data but have limitations to acquire periodical or long-term data. Offset tracking using SAR is actively being used as an alternative of in-situ measurements. Offset tracking has a limitation in that the accuracy of observation is lower than that of other observational techniques, but it has been improved by recent studies. Recent studies in the $Uv{\hat{e}}rsbreen$ glacier area have shown that glacier altitudes decrease at a rate of 1.5 m/year. The glacier displacement velocities in this region are heavily influenced by climate change and can be important in monitoring and forecasting long-term climate change. However, there are few concrete examples of research in this area. In this study, we applied the improved offset tracking method to observe the two-dimensional velocity in the $Uv{\hat{e}}rsbreen$ glacier. As a result, it was confirmed that the glacier moved at a maximum rate of 133.7 m/year. The measruement precisions for azimuth and line-of-sight directions were 5.4 and 3.3 m/year respectively. These results will be utilized to study long-term changes in elevation of glaciers and to study environmental impacts due to climate change.

• Journal of IKEEE
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• v.22 no.2
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• pp.281-288
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• 2018

In this paper, we propose an intelligent face recognition and tracking system that distributes GPU resources using CUDA. The proposed system consists of five steps such as GPU allocation algorithm that distributes GPU resources in optimal state, face area detection and face recognition using deep learning, real time face tracking, and PTZ camera control. The GPU allocation algorithm that distributes multi-GPU resources optimally distributes the GPU resources flexibly according to the activation level of the GPU, unlike the method of allocating the GPU to the thread fixedly. Thus, there is a feature that enables stable and efficient use of multiple GPUs. In order to evaluate the performance of the proposed system, we compared the proposed system with the non - distributed system. As a result, the system which did not allocate the resource showed unstable operation, but the proposed system showed stable resource utilization because it was operated stably. Thus, the utility of the proposed system has been demonstrated.

• The Journal of the Korea Contents Association
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• v.19 no.4
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• pp.102-110
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• 2019

Among the visual sensibility studies, many studies of color or movement have been done, but not much have been done about whether it can evoke sensibility in static form itself. Therefore, in this study, visual attention by AOIs(Area of Interests) combined with color based on three basic forms was analyzed using eye tracking, and the results were visually expressed through Heat Map and Gaze Plot. In addition, A Paired t-test was performed on the mean difference between the two groups to verify the statistical significance of each color and form. As a result of the experiment, the chromatic color form was more visual attention than the achromatic color form and warm color form was higher mean than cool color, so the visual attention was greater. In this study, it is meaningful to suggest a quantitative method which is easy to interpret objectively the design element that is easily interpreted subjectively. Based on the results of this study, if more further studies and quantitative analysis methods are presented that can identify differences in visual attention from various colors and forms, it can be used to provide guidelines for basic design.

• Investigative Magnetic Resonance Imaging
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• v.10 no.1
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• pp.1-7
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• 2006

Purpose : Recent development of diffusion tensor imaging enables the evaluation of the microstructural characteristics of the brain white matter. However, optimal imaging parameters for diffusion tensor imaging, particularly concerning the number of diffusion gradient direction, have not been studied thoroughly yet. The purpose of this study was to evaluate the influence of the number of diffusion gradient direction on the fiber tracking of the white matter. Materials and methods : 13 healthy volunteers (ten men and three women, mean age 30 years, age range 23-37 years) were included in this study. Diffusion tensor imaging was performed with different numbers of diffusion gradient direction as 6, 15, and 32, keeping the other imaging parameters constant. The imaging field ranged from 1 cm below the pons to 2-3 cm above the lateral ventricle, parallel to the anterior commissure-posterior commissure line. FA (fractional anisotropy) maps were created via image postprocessing, and then FA and its standard deviation were calculated in the genu and the splenium of the corpus callosum on each of FA maps. Fiber tracking of the corticospinal tract in the brain was performed and the number of the reconstructed fibers of the tract was measured. FA, standard deviation of FA and the number of the reconstructed fibers were compared statistically between the different diffusion gradient directions. Results : FA is not statistically significantly different between the different diffusion gradient directions. By increasing the number of diffusion gradient direction, standard deviation of FA decreased significantly, and the number of the reconstructed fibers increased significantly. Conclusion : The higher number of diffusion gradient direction provided better quality of fiber tracking.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2012.05a
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• pp.909-912
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• 2012

An automated cell tracking system is automatically to analyze and track changes of cell behaviors in time-lapse cell images acquired from microscope in the cell culture. In this paper, we proposed and developed an ellipse fitting based algorithm for separating very small size overlapping cells in a cell image consisted of thousands or ten thousands cells. We were extracted contours of clusters and divided them into line segments and then produced their fitted ellipses for each line segment. By experimentations, our algorithm was separated clusters with average 91% precision for two overlapping cells and average 84% precision for three overlapping cells respectively.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.23 no.1
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• pp.109-115
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• 2009

This paper describes an early detection for indication of electric accident using current waveform which is measured in electric equipments consisted incandescent lamps. At first, it analyzes characteristics of current monitor in resistive electric circuit. In second, the electric equipment is consisted of incandescent lamps. And the electric accident is simulation of tracking according to KS C IEC(Korea Standard C International Electrostatic Commission) 60112 at some part of the electric equipment. The indication of the electrical accident is detected to analyzing current waveform measured by current monitor. As the tracking breakdown, electric accident, processes, as current pulse is bigger and ratio of appearance also is increased irrespective of amount of load.