• Journal of the Korea Institute of Information Security & Cryptology
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• v.7 no.2
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• pp.27-42
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• 1997

We propose a new authentication and key distribution protocol which is efficient and reliable for password-based systems. Various guessing attacks have been detected in applying conventional protocols to the password-based systems and additional overheads have been made in refined protocols to defeat those attacks. Using a one-time pad and a strong hash function, our proposed protocol promotes reliability and efficiency. Compared with other protocols, our protocol is secure against various protocol attacks including guessing attacks. In addition, this protocol is efficient in reducing communication and computation costs.

• Proceedings of the Korea Information Processing Society Conference
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• 2011.04a
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• pp.1060-1063
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• 2011

인간은 목적지를 향하여 가는 방법의 선택에 있어서 가고자 하는 목적, 목적지, 출발 시간 등에 영향을 받는다. 그러나 이러한 매개변수들과 더불어 중요하게 고려되는 것은 바로 인간의 습관이다. 다시 말해 인간이 목적지로 가는 방법을 선택하는데 습관이라는 매개변수와 밀접한 영향이 있다는 것이다. 이를 미루어 볼 때, 인간의 이동은 습관으로 인해 대부분 특정한 범주 안에서 이동을 할 것이라는 추측할 수 있다. 나아가, 사람들이 흔히 들고 다니는 GPS장치에서 측정된 데이터가 추측한 속성으로 인해 범주를 벗어나는 이상현상을 검출하는 것으로 확장을 할 수 있다. 즉, GPS장치에서 측정된 데이터는 개인별로 클래스화(Classification)가 가능함을 추론할 수 있다. 본 논문에서는 실제 사람이 이동한 좌표를 바탕으로 시간당 변화량을 계산하여 좌표에 사상시켰다. 그리고, 단일 클래스 서포트 백터 머신(OCSVM)을 가지고 클래스화 했으며, OCSVM의 커널 함수 내의 변수인에 따라 클래스의 크기 혹은 클래스 내부의 밀도에 영향을 받음을 알 수 있었으며, 그 둘 사이에는 적절한 교환(Tradeoff)이 발생하였다는 결론이 나왔다.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2023.05a
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• pp.173-174
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• 2023

IAMSAR Manual 국문본인 국제항공 및 해상수색 구조편람에 따른 확대사각(SS: Expanding Square Search) 수색패턴은 수색 대상의 표류 위치를 한정할 수 있을 때 적용하도록 하고 있으며, 수색 기법에 있어 추측항법 적용의 필요성과 함께 조난대상의 표류 추정 위치인 Datum으로부터의 첫 번째 수색 방향 S의 결정은 바람이 불어오는 쪽인 풍상 측을 향하도록 하여 항해 오차를 최소화할 것을 요구하고 있다. 그러나 첫 직행 구간 S 결정에 있어 IAMSAR Manual 영문본 및 USCG SAR Manual에 따르면 S는 풍하 측 또는 표류하는 방향으로 결정하는 것이 옳은 것으로 해석될 수 있으며 이는 항해 오차를 최소화하기 위한 추측항법 적용 관점에도 부합하는 것으로 보이는바, 이 연구에서는 USCG SAR Manual 등 다른 수색 지침서에서는 Drift 방향으로 제시한 첫 번째 S 방향을 근거로 IAMSAR Manual 국문본의 오류 가능성을 제시하였고, 풍상과 풍하 측으로 상반된 첫 번째 S 방향에 따른 수색 결과의 비교를 위해 선박조종시뮬레이션을 활용, 확대사각 수색상황을 재연하여 각각의 수색패턴을 비교 분석하였다. 이를 통하여 확대사각 수색패턴 결과에서 수색 대상에 더욱 근접한 첫 번째 S 방향은 수색 대상이 표류하는 방향과 일치하는 풍하 측임을 확인하였다.

• Education of Primary School Mathematics
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• v.26 no.4
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• pp.257-275
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• 2023

In this study, we designed and implemented a instruction emphasizing mathematical argument for fifth-grade students and analyzed the teaching practices. Through a literature review related to instruction emphasizing mathematical argument, we organized a teaching model of five phases that explain why the general claim that the sum of consecutive odd numbers equals a square number is true: 1) noticing patterns, 2) articulating conjectures, 3) representing through visual model, 4) arguing based on representation, 5) comparing and contrasting. Then, we analyzed the argumentation stream by phases to observe how the instruction emphasizing mathematical argument is implemented in the elementary classroom. Based on the results of this study, we discuss the implications of teaching a mathematical argument in elementary school.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.48 no.6
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• pp.401-410
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• 2020

In this study, a real-time Tactical UAS position compensation system based on image information developed to compensate for the weakness of location navigation information during GPS signal interference and jamming / spoofing attack is described. The Tactical UAS (KUS-FT) is capable of automatic flight by switching the mode from GPS/INS integrated navigation to DR/AHRS when GPS signal is lost. However, in the case of location navigation, errors accumulate over time due to dead reckoning (DR) using airspeed and azimuth which causes problems such as UAS positioning and data link antenna tracking. To minimize the accumulation of position error, based on the target data of specific region through image sensor, we developed a system that calculates the position using the UAS attitude, EO/IR (Electric Optic/Infra-Red) azimuth and elevation and numerical map data and corrects the calculated position in real-time. In addition, function and performance of the image information based real-time UAS position compensation system has been verified by ground test using GPS simulator and flight test in DR mode.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.17 no.3
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• pp.32-45
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• 2018

This study aims to compare the mutual perception gap on dangerous driving behavior between male and female drivers in multiple aspects, analyze them, and identify factors that trigger this different perception. To understand the mutual perception gap on dangerous driving behavior, DBQ(Driving Behavior Questionnaire) was applied as a rating scale. By applying results into the Co-oreintation model, this study compared the mutual perception gap between male drivers and female drivers and analyze results. In addition, factors that generate the perception gap between both genders were drawn by analyzing factors. This study suggested that objective consistency identified the perception gap that driving behaviors of others were more dangerous between two genders. In addition, subjective consistency was different as both genders assumed that the counterpart's driving behavior takes more risks than their own actual driving behaviors. In regard to the accuracy, men were aware that female driving behaviors are more dangerous than their behaviors. However, female driving behavior assumed by women was consistent with male perception in all factors, which indicated that women perceive men precisely. In addition, results were compared and analyzed in both perspectives of male drivers and female drivers by combining predictive models. Based on these results, both genders perceived that counterpart's driving behavior is more dangerous among both genders.

• Journal of Advanced Navigation Technology
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• v.21 no.2
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• pp.171-178
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• 2017

In this paper, in order to verify the performance of a localization algorithm using GPS as an auxiliary sensor, the algorithm was applied to a hovering-type autonomous underwater vehicle (AUV) to perform a field test. The applied algorithm is an algorithm to improve the accumulated positional error of dead reckoning using doppler velocity logger(DVL) and tilt-compensated compass module (TCM) mounted on the AUV. GPS when surfaced helps the algorithm to estimate the position and the heading bias error of TCM for geodetic north, which makes it possible to perform dead reckoning on north-east-down (NED) coordinates. As a result of field test performing heading control, it was judged that the algorithm could improve the positional error, enhance the operational capability of AUV and contribute to the research of underwater navigation depending on a magnetic compass.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.17 no.5
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• pp.200-209
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• 2018

This study proposed a method to select existing facilities as a landmark in order to reset accumulated errors of dead reckoning in a tunnel difficult to receive GNSS signals in automated driving. First, related standards and regulations were reviewed in order to survey 'variety' on shapes and installation locations as a feature of facilities. Second, 'recognition' on facilities was examined using image and Lidar sensors. Last, 'regularity' in terms of installation locations and intervals was surveyed through related references. The results of this study selected a fire fighting box / lamp (50m), an evacuation corridor lamp (300m), a lane control system (500m), a maximum / minimum speed limit sign and a jet fan as a candidate landmark to reset positioning errors. Based on those facilities, it was determined that error correction was possible. The results of this study are expected to be used in repositioning of automated driving vehicles in a tunnel.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.20 no.2
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• pp.105-111
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• 1984

Recently, Hybrid Navigation Systems combining Omega, NNSS, Loran C and Dead reckoning etc. served to give us highly accurate ship's position, and a number of ships are equipped with these navigation systems. In order to evaluate for the accuracy of this navigation system observations of Loran C, 5970 and 9970 chains and Radar at the same time were made on board m.s Jeonbuk 401 and 403 training ships of Gunsan Fisheries Collage at nine stations in the yellow sea from July, 1982 to June, 1983, and then were done by the Hybrid Navigation System combining Dead reckoning and Loran C at the same areas. The authors investigated the accuracy of the Hybrid Navigation System based on measurements of the relative positional error which is defined as the difference between the position fixed by this system or the Loran C system, and the one by the Radar. The obtained results are as follows; 1. The mean standard deviation of the time difference of Loran C were about 0.21$\mu$s in 9970 chain and about 0.06$\mu$s in 5970 chain, and the fluctuation of the time difference of Loran C in 5970 chain was smaller than that in 9970 chain. 2. The positional error between two positions by Radar and the Hybrid Navigation System in 9970 chain was about 0.4 miles, and between two positions by Radar and Loran C was about 0.51 miles. The Hybrid Navigation System was therefore more accurate than Loran C System. 3. The positional error between two positions by Radar and Hybrid Navigation System in 5970 chain was about 0.4 miles, and between two positions by Radar and computer simulation of Loran C was about 0.98 miles. Consequently, Hybrid Navigation System was more accurate than computer simulation of Loran C system.

• Journal of the Korean Society of Food Science and Nutrition
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• v.32 no.7
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• pp.1076-1081
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• 2003

The effects of dietary supplementation of JR-22, formula containing distilled extracts of traditional herbs on maximal exercise performance and endurance were evaluated in mouse and rat model. In acute forced swimming test with 4%∼8% of the body weight attached to the tail, it was shown that dietary JR-22 supplementation increased endurance in exercise performance. There was no change of blood lactic acid, ammonia, inorganic phosphorous ion and creatine kinase activity, however ATP concentration in muscle was increased by JR-22 supplementation. Also, insulin-like growth factor-l (IGF-1) concentration in blood was significantly increased by JR-22 supplementation. In addition, the oxidative damage induced by exercise was reduced by JR-22 supplementation. In these results, we suggested that JR-22 supplementation enhanced maximal endurance exercise performance by the mechanism of increasing ATP and IGF-1 concentration and reducing oxidative damage.