• Journal of Internet Computing and Services
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• v.9 no.4
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• pp.157-166
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• 2008

There has been a renewal of interest in management of underground facility in recent years. As several research have been made on management for underground facility of waterworks pipe. In this paper smart-tag is defined and applied to requiring ubiquitous environment. Also, GPS is essential technology for the implementation of proposed program, which has GPS and RFID mixed business model. And it manages data of underground facility with RFID system effectively and provides the high quality practical effectiveness of entire system through GPS receiving module and network communication on GIS. In conclusion, this paper proposed applications management system with location mixed database. Proposed database and interface skill is tested and evaluated through the simulation.

• Journal of the Korea Institute of Military Science and Technology
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• v.15 no.6
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• pp.746-753
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• 2012

ROK military helicopters are frequently exposed to the hazard situations due to the characteristic of operation. Especially, helicopter accident may lead to critical damage of human and structure. Accordingly, pilots have to train the autorotation procedures and learn the skill to prevent hard landing. In this paper, the behavior of skid gear subject to the helicopter autorotation was conducted by using numerical method. The computer simulation approach by using finite element method was employed to accomplish this goal. Additionally, the behavior of skid gear was evaluated for the different landing conditions. In conclusion, the maximum stress concentration was occurred at the attached area of skid cross-tube to the fuselage. Also, it was revealed that the most proper attitude was level landing to prevent hard landing.

• Journal of the Korea Institute of Military Science and Technology
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• v.21 no.6
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• pp.817-825
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• 2018

Recently, drones have been used in various field to overcome time and space limitations. However, single drone still has a lot of restriction on transportation wight and travel time. Therefore many studies have been conducted to increase the utilization by swarm of drones. Many things should be additionally considered in order to operate swarming drones securely. Especially the group key management is a challenging research topic in tactical domain due to existence of adversary that has anti-drone skill. In this paper, we proposed an efficient group key management scheme for tactical swarming drone networks where an adversary equipped with anti-drone skills exists. The group key can be updated with a small number of message exchange compared to other convenience schemes. The numerical and simulation results demonstrate that the proposed scheme manages the group key efficiently and securely.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.43 no.4
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• pp.150-160
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• 2020

In this paper, we introduce a pilot's scheduling model which is able to maintain and balance their capabilities for each relevant skill level in military helicopter squadron. Flight scheduler has to consider many factors related pilot's flight information and spends a lot of times and efforts for flight planning without scientific process depending on his/her own capability and experience. This model reflected overall characteristics that include pilot's progression by basis monthly and cumulative flight hours, operational recent flight data and quickly find out a pinpoint areas of concern with respect to their mission subjects etc. There also include essential several constraints, such as personnel qualifications, and Army helicopter training policy's constraints such as regulations and guidelines. We presented binary Integer Programming (IP) mathematical formulation for optimization and demonstrated its effectiveness by comparisons of real schedule versus model's solution to several cases experimental scenarios and greedy random simulation model. The model made the schedule in less than 30 minutes, including the data preprocessing process, and the results of the allocation were more equal than the actual one. This makes it possible to reduce the workload of the scheduler and effectively manages the pilot's skills. We expect to set up and improve better flight planning and combat readiness in Korea Army aviation.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.19 no.5
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• pp.167-174
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• 2009

Recently, Li et al. proposed a new differential fault analysis(DFA) attack on the block cipher ARIA using about 45 ciphertexts. In this paper, we apply their DFA skill on AES and improve attack method and its analysis. The basic idea of our DFA method is that we recover intermediate ciphertexts in last round using final faulty ciphertexts and find out last round secret key. In addition, we present detail DFA procedure on AES and analysis of complexity. Furthermore computer simulation result shows that we can recover its 128-bit secret key by introducing a correct ciphertext and 2 faulty ciphertexts.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.22 no.6
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• pp.143-148
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• 2022

It is very important for metaverse, mobile robot, and user location services to analyze the images continuously taken using a mobile smartphone or robot's monocular camera to estimate the camera's location. So far, PnP-related techniques have been applied to calculate the position. In this paper, the camera's moving direction is obtained using the essential matrix in the epipolar geometry applied to successive images, and the camera's continuous moving position is calculated through geometrical equations. A new estimation method was proposed, and its accuracy was verified through simulation. This method is completely different from the existing method and has a feature that it can be applied even if there is only one or more matching feature points in two or more images.

• Atmosphere
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• v.27 no.1
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• pp.105-118
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• 2017

This study assesses the performance of the Weather Research and Forecasting (WRF) model in reproducing regional climate over CORDEX-East Asia Phase 2 domain with different cumulus parameterization schemes [Kain-Fritch (KF), Betts-Miller-Janjic (BM), and Grell-Devenyi-Ensemble (GD)]. The model is integrated for 27 months from January 1979 to March 1981 and the initial and boundary conditions are derived from European Centre for Medium-Range Weather Forecast Interim Reanalysis (ERA-Interim). The WRF model reasonably reproduces the temperature and precipitation characteristics over East Asia, but the regional scale responses are very sensitive to cumulus parameterization schemes. In terms of mean bias, WRF model with BM scheme shows the best performance in terms of summer/winter mean precipitation as well as summer mean temperature throughout the North East Asia. In contrast, the seasonal mean precipitation is generally overestimated (underestimated) by KF (GD) scheme. In addition, the seasonal variation of the temperature and precipitation is well simulated by WRF model, but with an overestimation in summer precipitation derived from KF experiment and with an underestimation in wet season precipitation from BM and GD schemes. Also, the frequency distribution of daily precipitation derived from KF and BM experiments (GD experiment) is well reproduced, except for the overestimation (underestimation) in the intensity range above (less) then $2.5mm\;d^{-1}$. In the case of the amount of daily precipitation, all experiments tend to underestimate (overestimate) the amount of daily precipitation in the low-intensity range < $4mm\;d^{-1}$ (high-intensity range > $12mm\;d^{-1}$). This type of error is largest in the KF experiment.

• Atmosphere
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• v.27 no.2
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• pp.133-150
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• 2017

This study evaluates CMIP5 model performance on rainy season evolution in the East Asian summer monsoon. Historical (1986~2005) simulation is analyzed using ensemble mean of CMIP5 19 models. Simulated rainfall amount is underestimated than the observed and onset and termination of rainy season are earlier in the simulation. Compared with evolution timing, duration of the rainy season is uncertain with large model spread. This area-averaged analysis results mix relative differences among the models. All model show similarity in the underestimated rainfall, but there are quite large difference in dynamic and thermodynamic processes. The model difference is shown in horizontal distribution analysis. BEST and WORST group is selected based on skill score. BEST shows better performance in northward movement of the rain band, summer monsoon domain. Especially, meridional gradient of equivalent potential temperature and low-level circulation for evolving frontal system is quite well captured in BEST. According to RCP8.5, CMIP5 projects earlier onset, delayed termination and longer duration of the rainy season with increasing rainfall amount at the end of 21st century. BEST and WORST shows similar projection for the rainy season evolution timing, meanwhile there are large discrepancy in thermodynamic structure. BEST and WORST in future projection are different in moisture flux, vertical structure of equivalent potential temperature and the subsequent unstable changes in the conditional instability.

• The Korean Journal of Emergency Medical Services
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• v.15 no.3
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• pp.5-17
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• 2011

purpose : The purpose of this study was to analyze the effect of basic life support performance by video simulation training. Methods : The subjects in this study consisted of 24 persons of experimental group and 24 persons of control group in freshmen and sophomore EMT students. The data were collected from September 1 to 30, 2010. Results : 1. Hypothesis one: experimental group is meaningful higher than control group at the operation point (p<0.05) of adult/infant's basic life support for one person. In subcategory that identifying breath, artificial respiration, pulse rate, 30 compressions, Ability to perform all the processes, the experimental group showed statistically higher score (p<0.05) than control group, and sequence from checking reaction to keeping airway management isn't statistically significant difference between experimental group and control. 2. Hypothesis two: In the hypothesis, the experimental group's point of adult basic life support by two persons and use of Automated External Defibrillator is good in experimental group than control group's point(p<0.05). As the result of researching 11 contents of check list about adult basic life support by two persons and Automated External Defibrillator(AED), by dividing into 7 subcategories, every subcategory shows that the experimental group is significant higher than control group(p<0.05). 3. Hypothesis three: In the hypothesis, the experimental group gets higher point of infant basic life support by one or two persons than the control group (p<0.05). As the results of researching 15 contents of check list about infant basic life support by one or two persons, by dividing into 8 subcategories, the experimental group is statistically meaningful higher (p<0.05) than the control group in process of keeping airway, indentifying breathing, identifying pulse, 30 compressions, Ability to perform all the processes. There isn't statistically significant difference between the groups in process of checking reaction, reporting 119, and artificial respiration by giving 2 breaths(p<0.05). Conclusion : As summarizing the results, the group, receiving using video, gets higher points of knowledge of basic life support and operating skill than the general educated group. It is found that the Video simulation training could be effective, because of these positive effects to improve clinical working performance of students, who participate in the department of Emergency Medical Technology.

• Journal of the Korea Convergence Society
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• v.12 no.1
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• pp.369-377
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• 2021

Augmented reality smart-glass enables healthcare providers to use patient and their care related information without interference of workflow. In addition, augmented reality smart-glass simulation had advantages in improving competency via remote collaboration and real-time information sharing. This study investigated perception and attitude regarding augmented reality smart glass based healthcare simulation on three different groups of healthcare major students, computer major students, developers and faculties. Using convenience sampling method, data were obtained from 95 participants and statistical analysis were performed using SPSS 25.0. Developer and faculty group showed the highest scores, followed by healthcare major students. There was the high expectation on augmented reality smart-glass for skill acquisition and the high performance and big screen were essential features of device. The findings of this study revealed that differences between healthcare and computer major students exist and strategies to reduce those gaps are required to adopt augmented reality smart glass in healthcare settings.