• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.39 no.5
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• pp.343-349
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• 2021

In The process from design to construction in the existing construction work was less efficient due to the contradictory approach of identifying the 3D state in the plan view and the repeated generation of surveys, floor plans, drawings. Accurate 3D design data is essential for smart construction. However, most of the existing related studies have focused on explaining the development method and main functions of equipment or improving the productivity of smart construction. Therefore, in this study, the utility of 3D design model generation for smart construction and construction survey using 3D laser scanner was evaluated. Plane and vertical road alignment were created using the specifications of the road. The generated road alignment was created as a three-dimensional corridor design using cross-sections at intervals of 20m. In addition, it was possible to create a DTM (Digital Terrain Model) using a digital map and effectively create a 3D design model for the study area through overlapping. Construction survey using a 3D laser scanner showed accuracy within 10cm as a result of the accuracy evaluation. These results proved that construction surveying using a 3D laser scanner is possible because it satisfies the acceptable accuracy of the relevant regulations modeling of target areas using 3D design and construction survey using 3D laser scanner can be a way to address shortcomings of existing GNSS (Global Navigation Satellite System) methods. And accurate 3D data will be used as essential data as basic data for smart construction.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.29 no.3
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• pp.613-628
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• 2019

In-Vehicle Infotainment provides navigation and various functions through the installation of the application. And infotainment is very important to control the entire vehicle by sending commands to the ECU. Infotainment supports a variety of wireless communication protocols to install and update applications. So Infotainment is becoming an attack surface through wireless communcation protocol for hacker's access. If malicious software is installed in infotainment, it can gain control of the vehicle and send a malicious purpose command to the ECU, affecting the life of the driver. Therefore, measures are needed to verify the security and reliability of infotainment software updates, and security requirements must be derived and verified. It must be developed in accordance with SDL to provide security and reliability, and systematic security requirements must be derived by applying threat modeling. Therefore, this paper conducts threat modeling to derive infotainment update security requirements. Also, the security requirements are mapped to the Common Criteria to provide criteria for updating infotainment software.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2014.05a
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• pp.672-674
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• 2014

Mobile communication technology was one of the GPS technology, SmartPhone, Tablet PC is equipped with a GPS. So the user has a navigation, speed and his position to send and receive a variety of information. Therefore, in this paper, Mobile devices, GPS, Wi-Fi and mobile networks, and the communication module uses algorithms to analysis of acceleration and output, the user is currently using the system to find out the kind of transportation. This is the users who are using a particular transport unnecessary information and apply it to different areas do not think I will be able to.

• Journal of the Korean Society of Marine Environment & Safety
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• v.25 no.1
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• pp.122-129
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• 2019

Due to its nature the manufacturing industry faces a cyclical economy, and therefore there is an urgent need for a companion industry to cope with this cyclic pattern in the long run. The sector suitable for meeting this demand is the repair and shipbuilding industry. In order to operate a shipbuilding repair business, a floating dock is indispensable, and most obsolete floating docks were imported from overseas and operated through repair/maintenance. However, there is no precise guideline for floating dock safety, and most models have been in use for at least 30 years without being required to enter classification at the time of operation. In this study, structural strength analysis was carried out using measured thickness information of aged floating docks, and the residual structural strength of floating docks in operation was analyzed. The main results derived from this study can be referred to as guidelines for the review of the structural safety of similar equipment, and it is expected that an optimal solution will be found within a short time using this method for repair/maintenance.

• Journal of the Korean Society of Marine Environment & Safety
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• v.25 no.5
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• pp.519-526
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• 2019

This study proposes a methodology for estimating the appropriate capacity of anchorage for ports requiring the establishment of waiting anchorage and then applying the methodology to the ports in Jinhae Bay to compare it with the anchorage capacity of major ports in Korea. To estimate the appropriate anchorage capacity, the "Anchorage Capacity Index" was used, which was calculated from the "Total Gross Tonnage" and "Simultaneous Anchoring Capacity". The calculations were made according to the anchorage capacity index of 0.89 of the target harbors. The adequate anchorage capacity index for the new waiting anchorage was analyzed at a level of 6.0. If the concept of anchorage capacity index suggested in this study is reflected as a new design criteria of waiting anchorage, it will be helpful for the safety of berth, safety of anchorage and effective operation of harbor.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.49 no.3
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• pp.251-262
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• 2021

The airworthiness certification of lightning indirect effects becomes an important issue in personal air vehicles (PAVs), which are being actively developed around the world. PAVs are very vulnerable to lightning strikes, because of miniaturization, use of the electric engines, composite materials, and application of unmanned navigation systems. In this study, we first examined various steps of certifications for lightning indirect effects shown in AC 20 136B issued by the Federal Aviation Administration (FAA). We then applied certification guidelines for equipment transient design level listed in RTCA DO 160G Section 22 to PAVs and investigated lightning transient environments inside the PAVs. We also analyzed the aircraft level tests specified in SAE ARP 5416A by using electromagnetic computational analysis software EMA3D. Finally, we analyzed the actual transient level for PAVs and derived the data necessary for conformity certification.

• Journal of Astronomy and Space Sciences
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• v.37 no.4
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• pp.237-247
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• 2020

The ground tracking support is a critical factor for the navigation performance of spacecraft orbiting around the Moon. Because of the tracking limit of antennas, only a small number of facilities can support lunar missions. Therefore, case studies for various ground tracking support conditions are needed for lunar missions on the stage of preliminary mission analysis. This study analyzes the ground supporting condition effect on orbit determination (OD) of Korea Pathfinder Lunar Orbiter (KPLO) in the lunar orbit. For the assumption of ground support conditions, daily tracking frequency, cut-off angle for low elevation, tracking measurement accuracy, and tracking failure situations were considered. Two antennas of deep space network (DSN) and Korea Deep Space Antenna (KDSA) are utilized for various tracking conditions configuration. For the investigation of the daily tracking frequency effect, three cases (full support, DSN 4 pass/day and KDSA 4 pass/day, and DSN 2 pass/day and KDSA 2 pass/day) are prepared. For the elevation cut-off angle effect, two situations, which are 5 deg and 10 deg, are assumed. Three cases (0%, 30%, and 50% of degradation) were considered for the tracking measurement accuracy effect. Three cases such as no missing, 1-day KDSA missing, and 2-day KDSA missing are assumed for tracking failure effect. For OD, a sequential estimation algorithm was used, and for the OD performance evaluation, position uncertainty, position differences between true and estimated orbits, and orbit overlap precision according to various ground supporting conditions were investigated. Orbit prediction accuracy variations due to ground tracking conditions were also demonstrated. This study provides a guideline for selecting ground tracking support levels and preparing a backup plan for the KPLO lunar mission phase.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.38 no.6
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• pp.689-696
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• 2020

It is known through prior research that the crust of the Korean Peninsula moves southeast at an annual average of 3 cm/year. The 2011 Great East Japan Earthquake caused a great change in the crust of the Korean Peninsula. Since then, the frequency of earthquakes has increased on the Korean Peninsula. Therefore, by using NGII and IGS GNSS observation data of the recent 15 years, to analyze the trends of changes in the deformation of the Korean Peninsula before and after the outbreak of the Great East Japan Earthquake. Data processing utilized Bernese Software V5.2, a widely used scientific and technical software around the world. As a result, the global movement of the Korean peninsula differed by about 4mm and the direction of movement by about 10° compared to before the Great East Japan Earthquake. As for the internal distortion of the Korean Peninsula, the East-West expansion of the Korean peninsula's crust was observed during the Great East Japan Earthquake, but it is believed that it has not fully returned to the level before the Great East Japan Earthquake.

• Journal of the Korean Society of Marine Environment & Safety
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• v.28 no.1
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• pp.91-99
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• 2022

The shipping industry is a service industry that operates its business by transporting cargo on ships and receiving freight. Therefore, large-scale capital investment is required for ship operation, and if the value of the ship is uncertain, the risk of shipping management increases. This study aims to identify the factors affecting changes in ship value and to analyze the importance of each variable. To achieve the goal, the factors affecting changes in ship value were identified and structured using the techniques of text mining and topic modeling, and classified into three main factors and 12 sub-factors. This study used AHP analysis to examine the relative importance of each factor. Results indicated that the main factor influencing the change in the vessel value was the shipping factor, followed by the investment factor and the environment factor. Other auxiliary factors that substantially affect the ship value include the volatility of the shipping market and of shipping freight.

• Journal of the Korea Convergence Society
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• v.12 no.11
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• pp.69-80
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• 2021

Neural machine translation using deep neural network has emerged as a mainstream research, and an abundance of investment and studies on model structure and parallel language pair have been actively undertaken for the best performance. However, most recent neural machine translation studies pass along decoding strategy to future work, and have insufficient a variety of experiments and specific analysis on it for generating language to maximize quality in the decoding process. In machine translation, decoding strategies optimize navigation paths in the process of generating translation sentences and performance improvement is possible without model modifications or data expansion. This paper compares and analyzes the significant effects of the decoding strategy from classical greedy decoding to the latest Dynamic Beam Allocation (DBA) in neural machine translation using a sequence to sequence model.