• KSCE Journal of Civil and Environmental Engineering Research
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• v.31 no.2D
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• pp.193-201
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• 2011

The provision of traffic information plays an important role in increasing social benefit not only by saving travel time for individuals but also by improving the efficiency of road operation. VMS(Variable Message Sign) helps on-wheel drivers easily understand the road situation, and also provides real-time traffic information to people on the streets. However, it has not been sufficiently studied on how traffic information based on VMS influences on the drivers' selection of route. This study investigated how drivers use VMS traffic information and how they are satisfied with it. Then, the model of drivers' route selection was specified with the types of traffic information and the expected travel time to examine the influence on the selection of drivers' route. The model was estimated and analyzed in three types according to the condition of detour roads, and the rate of route change and the degree of sensitivity was calculated from the estimation. The results of analysis are as follows. the $1^{st}$ type model showed the 10% of route change for the travel time saving of 5minutes, and the 81.6% of route change for the travel time saving of 20minutes. The $2^{nd}$ type led to the range of route change from 14.2% to 92.7% over the 5 through 20 minutes of travel time saving. The $3^{rd}$ model resulted in the 99.1% of route change. The sensitivity of route change showed the highest for the travel time saving of 11 minutes with the $1^{st}$ type model, 9 minutes with the $2^{nd}$ type model, and 5 minutes with the $3^{rd}$ type model respectively.

• Journal of Korean Tunnelling and Underground Space Association
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• v.19 no.5
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• pp.749-760
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• 2017

Recently, the proportion of tunnel structures in roads and railways has increased rapidly. Along with this trend, the rate of occurrence of cracks and dropouts in concrete lining of tunnel structures is increasing. Generally, maintenance of such concrete lining is normalized and managed as the core of maintenance work in tunnel maintenance. However, the maintenance of the tunnel pavement is important in securing driver in the tunnel. In the design of tunnels, the underground condition of the tunnel is designed to be in good rock condition, so there have not been many cases of cracks in the tunnel pavement in the past. Recently, the construction of tunnel structures has been rapidly increased, and the length of the tunnels has become longer.Tunnel pavement installed in these ground conditions is increasing the occurrence of cracks in the pavement due to decrease of bearing capacity of the pavement after a long time. In this study, FWD and GPR were conducted to analyze the types of cracks and the reduction of bearing capacity in the tunnel.

• Nuclear industry
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• v.37 no.9
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• pp.58-90
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• 2017

'공포의 값비싼 대가(The High Cost of Fear)'는 공개된 자료 중 동료 평가를 마친 최신의 자료와 간단한 계산 방법을 통해 한국의 탈원전 정책이 가져올 경제적, 환경적 영향을 분석한 보고서이다. 우리는 탈원전 정책이 다음과 같은 영향을 미칠 것으로 예측한다. ${\cdot}$천연가스 구매에만 최소 매년 100억 달러의 비용이 들 것이다. 이는 한국 평균임금인 연소득 29,125달러를 받는 일자리 343,000개에 해당하는 금액이다. ${\cdot}$비용의 대부분은 연료 수입에 사용될 것이며, 한국의 무역 수지가 악화될 것이다. ${\cdot}$한국의 부족한 재생에너지 자원을 고려할 때, 상당한 양의 화석 연료를 추가로 사용하게 될 것이다. ${\cdot}$LNG 발전소가 석탄 발전소를 대체하지 못하고 원자력발전소를 대체하면서 대기 오염으로 인한 조기 사망자 수가 증가할 것이다. ${\cdot}$한국의 전도유망한 원전 수출 산업이 아예 붕괴되거나 큰 타격을 입을 것이다. ${\cdot}$평균적 미국 자동차의 연간 주행거리를 기준으로 150만대에서 270만대의 미국 자동차가 배출하는 배기가스의 양만큼 연간 탄소 배출이 증가할 것이고, 한국은 파리기후협정에서 약속한 탄소 배출 감축 목표를 달성할 수 없게 된다. 본 보고서는 현재 계획된 탈원전 정책의 역사적 사회적 배경을 분석하여 다음과 같은 결론을 도출하였다. ${\cdot}$'그린피스(Greenpeace)', '지구의 친구들(Friends for the Earth)' 등 막대한 자금 지원을 받는 해외 환경단체들은 탈원전 거짓 정보의 근원이며, 이들은 저렴하고 풍부한 에너지라는 개념을 반대한다. ${\cdot}$후쿠시마 원전 사고와 그 여파의 주된 원인은 일본 원자력산업계의 오만과 원자력에 대한 과장된 집단 공포이다. ${\cdot}$반핵 진영의 논리에는 산업계와 정부에 대한 불신과 원자력, 방사선에 대한 몰이해가 반영되어 있다. ${\cdot}$반핵 진영은 후쿠시마 사고를 2014년 한수원 납품 비리 사태의 심각성을 과장하는 데 사용하고 있다. 2014년의 비리 사태는 한국 원자력 규제기관의 독립성을 증명했으며, 2016년의 경주 지진은 2011년 후쿠시마에서 쓰나미와 노심 용융을 초래한 동일본 대지진의 1/350,000의 크기밖에 되지 않는다. 본 보고서는 한국과 타국가의 반핵 운동이 주는 교훈을 다음과 같이 정리하였다. ${\cdot}$어떠한 국가도 에너지 자원 최빈국인 프랑스나 한국 같은 국가조차도 탈원전 '전쟁'에서 자유롭지 않으며, 이는 전 세계적으로 원자력산업이 쇠퇴하는 원인이다. ${\cdot}$원자력산업계, 정부, IAEA 등은 한국과 세계 여러 국가에서- 문화적, 제도적, 재정적 원인으로 원자력산업의 보호와 확대라는 목표를 달성할 수 없다. ${\cdot}$원자력산업을 구하기 위해서는 새로운 비전과 새로운 제도, 그리고 새로운 리더십이 필요하다. ${\cdot}$원자력의 근원적이고 혁신적인 비전 원자력 인본주의(atomic humanism)에 대한 재조명이 필요하다. ${\cdot}$원자력을 지키고 대중과 소통하기 위해 과학 연구단체, 대학교, 사단법인, NGO 등의 새로운 기관들을 후원해야 한다. ${\cdot}$공포를 조장하는 반원전 세력에 맞서 공포를 극복해야 하고, 대중의 공포를 극복해왔던 다른 기술들의 사례에서 교훈을 얻어야 한다.

• Journal of the Korea Convergence Society
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• v.11 no.9
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• pp.1-6
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• 2020

In this study, we propose an association inference model based on data bias optimization for road hazard detection. This is a mining model based on association analysis to collect user's personal characteristics and surrounding environment data and provide traffic accident prevention services. This creates transaction data composed of various context variables. Based on the generated information, a meaningful correlation of variables in each transaction is derived through correlation pattern analysis. Considering the bias of classified categorical data, pruning is performed with optimized support and reliability values. Based on the extracted high-level association rules, a risk detection model for personal characteristics and driving road conditions is provided to users. This enables traffic services that overcome the data bias problem and prevent potential road accidents by considering the association between data. In the performance evaluation, the proposed method is excellently evaluated as 0.778 in accuracy and 0.743 in the Kappa coefficient.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.42 no.5
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• pp.741-749
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• 2022

Major space agencies are planning for the rover-based lunar exploration since water-ice was detected in permanently shadowed regions (PSR). Although sunlight does not directly reach the PSRs, it is expected that reflected sunlight sustains a certain level of low-light environment. In this research, the indoor testbed was made to simulate the PSR's lighting and topological conditions, to which low light enhancement methods (CLAHE, Dehaze, RetinexNet, GLADNet) were applied to restore image brightness and color as well as to investigate their influences on the performance of feature extraction and matching methods (SIFT, SURF, ORB, AKAZE). The experiment results show that GLADNet and Dehaze images in order significantly improve image brightness and color. However, the performance of the feature extraction and matching methods were improved by Dehaze and GLADNet images in order, especially for ORB and AKAZE. Thus, in the lunar exploration, Dehaze is appropriate for building 3D topographic map whereas GLADNet is adequate for geological investigation.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.5
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• pp.409-416
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• 2020

Artificial intelligence, which is in the spotlight as the core driving force of the 4th industrial revolution, is expanding its scope to various industrial fields such as smart factories and autonomous driving with the development of high-performance hardware, big data, data processing technology, learning methods and algorithms. In the field of defense, as the security environment has changed due to decreasing defense budget, reducing military service resources, and universalizing unmanned combat systems, advanced countries are also conducting technical and policy research to incorporate artificial intelligence into their work by including recognition systems, decision support, simplification of the work processes, and efficient resource utilization. For this reason, the importance of technology-driven planning and investigation is also increasing to discover and research potential defense future technologies. In this study, based on the research data that was collected to derive future defense technologies, we analyzed the characteristic evaluation indicators for future technologies in the field of artificial intelligence and conducted empirical studies. The study results confirmed that in the future technologies of the defense AI field, the applicability of the weapon system and the economic ripple effect will show a significant relationship with the prospect.

• Korean Journal of Applied Biomechanics
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• v.18 no.4
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• pp.109-114
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• 2008

The purpose of this study was to estimate the energy expenditure simply and practically during physical activities. The physical activity is quantified by the integration of the accelerometer signals obtained from the triaxial accelerometer attached at the waist level of the human body. To find a relationship between energy expenditure and accelerometer data, 6 male and 5 female subjects walked and ran on the treadmill with speeds of 1.5, 3.0, 4.5, 6.0, 6.5, 7.0, and 8.5 km/hr. Each subject performed walking at the speed lower than 6.0 km/hr and running at the speed higher than 6.5 km/hr. Actual energy expenditure was determined by a continuous direct gas analyzer. Two predictive equations of walking and running mode for energy expenditure which includes gender, body mass index(BMI) and data from accelerometer were developed using multiple regression analysis. The correlation coefficients and coefficients of determination between the estimated and measured energy expenditure were R=0.936, R2=0.876 and R=0.881, R2=0.776 in walking and running mode, respectively. For further study, experiments on a larger scale of test subjects are essential for acquiring more reliable results.

• Proceedings of the Korean Society for Rock Mechanics Conference
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• 2008.03a
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• pp.51-68
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• 2008

When the train enters into a tunnel a high speed, pressure waves are generated inside the tunnel. The pressure waves at propagate in a form of compression wave toward the tunnel exit and a fraction of the compression waves that arrives at the exit of the tunnel are discharged to outside of the tunnel and the remainder is reflected into the tunnel as expansion waves. The compression waves emitted from the tunnel does not radiate in a specific direction but in all directions. If the amplitude of the compression wave is great, it causes noise and vibration, and it is called "Micro-Pressure Wave." "Micro-Pressure Wave" must be considered as a decision for the optimum tunnel cross-section as the amplitude of the compression wave depends on train speed, tunnel length, area of tunnel and train. Therefore, this paper introduces the case study of Micro-Pressure Wave characteristics for determination of tunnel cross section in Honam high speed railway, the pressure inside the tunnel and the micro-pressure waves at tunnel exit were measured at Hwashin 5 tunnel in Kyungbu HSR line. At the same time. a test of train operation model was performed and then the measurement results and test results were compared to verify that the various parameters used as input conditions for the numerical simulations, which were appropriate. Also a model test was performed, in order to analysis of the Micro-Pressure Wave Mitigation Performance by Type of Hood at Entrance Portal.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2009.10a
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• pp.108-111
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• 2009

In this paper, the development of unmanned vehicle systems to analysis applicable communications and alternative IEEE 802.11a. IEEE 802.11b/g uses the 2.4GHz. So, using the 5GHz OFDM in IEEE 802.11a interference phenomenon better. IEEE 802.11a has a maximum speed of 54Mbps. Indoors and apartment parking on experiment to soft roaming, hard roaming. Test equipments are AP four units(RSU), reliable results for the AP one unit Bridge, Switch one unit, one server notebook, one notebook(OBU), one car. Use Softwares are Wireshark, Jperf, Ping and million second transfer was used to develop the program. So the actual car was similar to the environment. With the results of the experiment for the unmanned vehicle systems will provide the best method.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.12 no.2
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• pp.170-177
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• 2019

In this paper, three theories for improving the stability of quadruped robot are presented. First, the Minimum-Jerk Trajectory is used to optimize the leg trajectory. Second, we compare the newly proposed sine wave and the conventional LSM in this paper based on the Jerk value. Third, we calculate the optimum stride of the sway through repetitive robot simulation using ADAMS-MATLAB cosimulation. Through the above process, the improvement of the robot walking is compared with the existing theory. First, the average gradient of the point where the leg trajectory changes rapidly was reduced from at least 1.2 to 2.9 by using the Minimum-Jerk targetory for the movement of the body and the end of the leg during the first walk, thereby increasing the walking stability. Second, the average Jerk was reduced by 0.019 on the Z-axis, 0.457 on the X-axis, and 0.02, 3D on the Y-axis by 0.479 using the Sin wave type sways presented in this paper, rather than the LSM(Longitude Stability Margin) method. Third, the length of the optimal stride for walking at least the Jerk value was derived from the above analysis, and the 20cm width length was the most stable.