• The Journal of Korean Institute of Communications and Information Sciences
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• v.30 no.12C
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• pp.1239-1247
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• 2005

It is important to improve TCP performance in Self-similar TCP network where signalling between the same end nodes through bidirectional traffic routes. In wireless link, the traffic limitation pattern occurred in two or more TCP connections is applied into MPEC video control as multi time-interval congestion control. For TCP update variable, we extend TCP and perform as function call, and we study a method of relating TCP with LTS module controlling with the information type that is overcoming the limit of feedback loop determined by RTT. For comparison, we measure the TCP throughput without LTS and verify the fairness by means of meta control. The improved TCP performance is shown by that the number of connections of traffic congestion control increases when RTT increases.

• Journal of the Institute of Electronics Engineers of Korea SC
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• v.47 no.1
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• pp.67-75
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• 2010

This paper presents localization algorithm for mobile robot in outdoor environment. Outdoor environment includes the uncertainty on the ground. Magnetic sensor or IMU(Inertial Measurement Unit) has been used to estimate robot's heading angle. Two sensor is unavailable because mobile robot is electric car affected by magnetic field. Heading angle estimation algorithm for mobile robot is implemented using gyro sensor module consisting of 1-axis gyro sensors. Localization algorithm applied Extended Kalman filter that utilized GPS and encoder, gyro sensor module. Experiment results show that proposed localization algorithm improve considerably localization performance of mobile robots.

• Proceedings of the Korea Water Resources Association Conference
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• 2012.05a
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• pp.767-771
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• 2012

남강댐은 평지에 위치하여 댐 높이가 낮고 댐운영 수위의 편차가 작기 때문에 계획홍수위 아래 완경사 비탈면이 갈수기인 3월부터 5월 사이에 장기간 노출되어 5월 전후에 발아하는 식생 특히, 버들류가 이입, 성장하여 대규모 군락을 이루고 있다. 현재 형성된 대규모의 버들류 군락은 댐수질을 악화시킬 뿐만 아니라 자기솎음질(self-thinning)에 의해 고사한 버들류의 유목으로 인하여 댐운영에 많은 애로를 초래하고 있다. 본 연구에서는 버들류 군락 형성과 댐운영수위와의 상관관계를 도출하여 버들류를 적절하게 제어할 수 있는 댐운영 방안을 마련하기 위한 기초자료로 활용하고자 하였다. 따라서, 버들류의 이입시점을 명확히 파악하기 위하여 현재의 남강댐 건설 직후인 1979년, 2003년 2010년의 항공사진과 수심측량에 의한 지형도를 이용하여 버들류 군락의 확장 경향을 분석하였다. 또한, 버들류의 이입시점을 명확히 파악하기 위하여 방형구를 설치하여 버들류의 밀도 및 흉고직경을 조사하고, 성장추에 의한 수령을 조사, 분석하였다. 연구결과를 요약하면 다음과 같다. 남강댐 연안대에 분포하는 버들류는 총 17종이며, 출현빈도가 높은 종은 선버들(Salix nipponica), 버드나무(Salix nipponica), 왕버들(Salix gracilistyla), 등으로서 선버들(Salix nipponica)이 우점종인 것으로 조사되었다. 남강댐 연안대에 분포하는 버들류의 수령을 조사한 결과 수령은 약 9년~10년, 흉고직경 10~15cm, 수고 7~8m인 것으로 조사되었다. 댐운영수위와 버들류의 수령을 분석한 결과 2002년 5월 댐수위 38.5~41.0m 일 때 연안대의 수면부근에서 1단계로 이입, 정착한 것으로 보이며, 2004년 및 2005년 5월경에 댐수위 36m일 때 2단계로 이입, 정착하여 현재 대규모 군락을 형성한 것으로 추정된다. 남강댐 버들류 군락의 형성은 버들류의 발아기에 댐수위 부근의 습지에서 발아환경이 최적인 온도와 저토환경에서 일시에 이입, 성장한 것으로 보인다. 따라서, 남강댐과 같이 평야부에 위치한 댐에서 댐운영 및 댐수질에 영향을 미치는 버들류를 제어하기 위해서는 버들류의 발아기에 댐운영 수위를 최대한 높여 현재의 버들류 군락에 의하여 발아, 성장이 불가능하도록 하거나 아니면 댐운영 수위를 낮추어 발아해도 홍수기 동안 장기간의 침수에 의하여 고사되도록 하는 댐운영 방안을 마련해야 할 것이다.

• Journal of Korean Philosophical Society
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• v.147
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• pp.29-58
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• 2018

The purpose of this article is to demonstrate that Hegel's philosophy of right is a dialectic critique of liberalism. The dialectical criticism in this article does not mean the formal logical denial, but a return to self by self-negation. Thus, if Hegel's philosophy of right is a dialectical critique of liberalism, Hegel's philosophy of right will be critical of liberalism and at the same time, it will not reject liberalism, but rather have aspects of liberalism. The criticism of liberalism implies that individual freedoms and rights can not be realized subjectively through individual free acts, but are realized intersubjectively through social mediums. And this is also found in controversies among modern liberalists because modern liberalism requires the government's role and institutional arrangements for the realization of individual freedoms and rights. We can find the aspects of liberalism in Hegel's philosophy of right since Hegel's ethical life entails ultimately the concrete realization and extension of individual freedom and rights.

• Journal of the Korea Convergence Society
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• v.12 no.12
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• pp.161-167
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• 2021

The purpose of this study is to provide a solution through a methodological approach so that character education can be naturally acquired in team-based learning activities. In the spring semester of 2021, a total of 69 college students in two groups were studied, and as a result of the study, the total score of character education virtues in the post-test was greatly improved in the experimental group (p<.001). The correlation between sub-items of team-based learning and pre and post-test results for character sub-items, self-regulation, consideration, communication, self-esteem, and responsibility, were statistically significant. This study shows character education through team-based learning had positive results. However, future research through a wider range of subjects is needed, and various teaching methods are being applied to propose verification of the effectiveness of character education.

• The Journal of the Korea Contents Association
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• v.21 no.12
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• pp.645-661
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• 2021

Scriptwriters have appeared in Korea's broadcasting production system for more than 40 years as a key producer. This study specifically investigated the work identity and labor experience of scriptwriters who have played countless roles from planning and organizing programs in various broadcast genres such as non-drama informative program, entertainment, news, and radio to script writing. As a result of examining the work identity and labor experience of the scriptwriters based on the auto-ethnography of the 20 scriptwriters working in the field, they felt that they had an " indispensable" program producer and a media culture producer and at the same time felt that they were taking on tasks that were unclear. They felt that the cause of this inequality was a problem of the production system and employment type, but they recognized that they could not be solved individually, and they were developing their own skills or building connections to get work, and expanding their areas unconditionally.

• Journal of the Korea Computer Graphics Society
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• v.29 no.3
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• pp.149-158
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• 2023

HMD, which is applied with the latest technology, minimizes motion sickness with high-resolution displays and fast motion recognition, and can accurately track location and motion. This can provide an environment where you can immerse yourself in a virtual three-dimensional space, and virtual reality contents such as disaster simulators and high-risk equipment learning spaces are developing using these characteristics. These advantages are also applicable in the field of basic science education. In particular, expanding the concepts of electric and magnetic fields in physics described by existing two-dimensional data into three-dimensional spaces and visualizing them in real time can greatly help improve learning understanding. In this paper, realistic physical education environments and contents based on three-dimensional virtual reality are developed and the developed learning contents are experienced by actual learning subjects to prove their effectiveness. A total of 46 middle school and college students were taught and experienced in real time the electric and magnetic fields expressed in three dimensions in a virtual reality environment. As a result of the survey, more than 85% of positive responses were obtained, and positive results were obtained that three-dimensional virtual space-based physical learning could be effectively applied.

• Clinical and Experimental Pediatrics
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• v.48 no.3
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• pp.321-326
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• 2005

Kawasaki disease is an acute systemic vasculitis of unknown origin. Giant coronary aneurysm is one of the most serious complications, although peripheral artery vasculitis can produce life-threatening events. Myocardial ischemia and infarction can be caused by coronary artery stenosis, aneurysm, and stagnation of blood flow in coronary arteries which triggers thromboembolism. Atypical presentation in young infants often interferes with prompt diagnosis and timely treatment, resulting in poor outcomes. We describe a 3-month-old infant with multiple giant coronary aneurysms with flow stagnation, stenosis and large mural thrombus due to Kawasaki disease. He presented with a prolonged course of severe coronary involvement in spite of all measures to reduce coronary complications. Finally, surgical intervention was tried because of the worsening coronary artery abnormalities. The patient died of acute cardiorespiratory failure shortly after weaning from cardiopulmonary bypass.

• Journal of the Korean Society of Radiology
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• v.5 no.5
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• pp.289-294
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• 2011

The aim of this study is to evaluate the differences of ejection fraction of left ventricle through the quantitative analysis of diastolic and systolic volumes according to slices selected using cardiac MR imaging. A total of 12 volunteers (7 normal, 1 myocardium bridge, and 4 arrhythmia) underwent cardiac MRI on a MR scanner(Magnetom Trio, Siemens, Germany). Ejection fractions for quantitative analysis were calculated at single slice of center of left ventricle, 3, 5, and 6-7 slices extending from the center of left ventricle. Average values were analyzed for evaluating differences of ejection fraction according to the number of slices selected. Mean value of normal person of ejection fraction were 67.14% at single slice of center of left ventricle, 66.24% at 3 slices, 65.63% at 5 slices, and 65.29% at 6-7 slices. While ejection fraction obtained from a patient with 61.74% at single slice of center of left ventricle, 60.92% at 3 slices, 60.89% at 5 slices, and 61.89% at 6-7 slices. There was no significant differences by the number of slices selected. This study demonstrates that ejection fraction obtained from single slice of center of left ventricle may represent a optimum parameter for cardiac function, instead of the value calculated on the variable slices selected.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.34 no.8
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• pp.1119-1127
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• 2010

In this paper, the design and nonlinear simulation of a multistable electromagnetic microactuator, which provides four stable equilibrium positions within its operating range, have been discussed. Quadstable actuator motion has been made possible by using both X- and Y-directional bistable structures with snapping curved beams. Two pairs of the curved beams are attached to an inner frame in both X- and Y-directions to realize independent bistable behavior in each direction. For the actuation of the actuator at the micrometer scale, an electromagnetic actuation method in which Lorentz force is taken into consideration was used. By using this method, micrometer-stroke quadstability in a plane parallel to a substrate was possible. The feasibility of designing an actuator that can realize quadstable motion by using the electromagnetic actuation method has been thoroughly clarified by performing nonlinear static and dynamic analyses and electrothermal coupled-field analysis of the multistable microactuator.