• Journal of Korean Society of Rural Planning
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• v.23 no.1
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• pp.21-29
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• 2017

The purpose of this study is to analyze the accuracy of cultivated crop database in agricultural farm business using UAV(Unmanned Aerial Vehicle) and field survey over Daesso-myeon, Umsung-gun, Chungbuk. When comparing with agricultural farm business and cadastral maps, Daeso-myeon crop field shows 29.8%(2,030 parcels out of 6,822 parcels) is either mismatched or missing. It covers almost 19.3%($3.4km^2$ of $17.6km^2$) of total farmland. In order to solve these problems, it is necessary to prepare a multifaceted plan including cadastral map. Comparative analysis of the cultivated crop registered in the agricultural farm business and the field survey agreed only in 3,622 parcels in total 6,822 parcels whereas 3200 parcels disagree. Among these disagreed parcels 2,030(29.8%) have been confirmed as unregistered farm business entity. Accuracy of cultivated crop registered in agricultural farm business agreed in 75.6% cases. Especially the paddy field registration is more accurate that other crops. These discrepancies can lead to false payment in agricultural farm business. For exploration and analysis of regional resources, UAV images can be used together with farm business management database and cadastral map to get a clearer grasp over on-site resources and conditions.

• Journal of the Korean Society for Aviation and Aeronautics
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• v.18 no.4
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• pp.73-79
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• 2010

Flight test is the final and a mandatory process for the development of unmanned aerial vehicles(UAVs) as well as manned. Since most UAVs fly in a low speed and are prone to adverse weather conditions such as air turbulence, atmospheric weather environment around flight test regions will be a critical item to be considered for a flight test planning for UAVs. In this paper, we suggest a decision method for a UAV flight test schedule based on weather conditions of surface and upper atmospheres and also introduce a program for an effective flight test planning through weather forecasts.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2008.03a
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• pp.579-582
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• 2008

PEM Fuel cell system was designed and constructed to use as a power source of unmanned aerial vehicles(UAV) in the present study. Sodium borohydride was selected as a hydrogen source and was decomposed by catalytic hydrolysis reaction. Fuel cell system consists of a fuel cell stack, a hydrogen generation system(HGS), and power management system(PMS). HGS was composed of a catalytic reactor, micropump, fuel cartridge, and separator. Hybrid power system between lithium-polymer battery and fuel cell was developed. The fuel cell system was integrated and packaged into a blended wing-body UAV. Energy density of the total system was 1,000 $W{\cdot}hr/kg$ and high endurance more than 5 hours was accomplished in the ground tests.

• Korean Journal of Remote Sensing
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• v.39 no.1
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• pp.87-97
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• 2023

Unmanned aerial vehicles (UAVs) can capture high-resolution imagery from a variety of viewing angles and altitudes; they are generally limited to collecting images of small scenes from larger regions. To improve the utility of UAV-appropriated datasetsfor use with deep learning applications, multiple datasets created from variousregions under different conditions are needed. To demonstrate a powerful new method for integrating heterogeneous UAV datasets, this paper applies a combined segmentation network (CSN) to share UAVid and semantic drone dataset encoding blocks to learn their general features, whereas its decoding blocks are trained separately on each dataset. Experimental results show that our CSN improves the accuracy of specific classes (e.g., cars), which currently comprise a low ratio in both datasets. From this result, it is expected that the range of UAV dataset utilization will increase.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.32 no.5
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• pp.737-750
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• 2022

The demands of Unmanned Aerial Vehicles (UAVs) are growing very rapidly with the era of the 4th industrial revolution. As the technology of the UAV improved with the development of artificial intelligence and semiconductor technology, it began to be used in various civilian fields such as hobbies, bridge inspections, etc from being used for special purposes such as military use. MAVLink (Macro Air Vehicle Link), which started as an open source project, is the most widely used communication protocol between UAV and ground control station. However, MAVLink does not include any security features such as encryption/decryption mechanism, so it is vulnerable to various security threats. Therefore, in this study, the block cipher is implemented in UAV to ensure confidentiality, and the results of the encryption and decryption performance evaluation in the UAV according to various implementation methods are analyzed. In addition, we proposed the security requirements in accordance with Common Criteria, which is an international recognized ISO standard.

• Journal of Positioning, Navigation, and Timing
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• v.4 no.2
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• pp.57-65
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• 2015

Global Navigation Satellite System (GNSS) including Global Positioning System (GPS) is an important element for navigation of both the military and civil Unmanned Aerial Vehicle (UAV). Contrary to the military UAVs, the civil UAVs use the civil signals which are unencrypted, unauthenticated and predictable. Therefore if the civil signals are counterfeited, the civil UAV’s position can be manipulated and the appropriate movement of the civil UAV to the target point is not achieved. In this paper, spoofing on the autonomous navigation UAV is implemented through field experiments. Although the demanded conditions for appropriate spoofing attack exists, satisfying the conditions is restricted in real environments. So, the Way-point of the UAV is assumed to be known for experiments and assessments. Under the circumstances, GPS spoofing signal is generated based on the Software-based GNSS signal generator. The signal is emitted to the target UAV using the antenna of the spoofer and the effect of the signal is analyzed and evaluated. In conclusion, taking the UAV to the target point is hardly feasible. To implement the spoofing as expectation, the position and guidance system of the UAV has to be known. Additionally, the GPS receiver on the UAV could be checked whether it appropriately tracks the spoofing signal or not. However, the effect of the spoofing signal on the autonomous UAV has been verified and assessed through the experimental results. Spoofing signal affects the navigation system of the UAV so that the UAV goes off course or shows an abnormal operation.

• Journal of the Korean Association of Geographic Information Studies
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• v.27 no.2
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• pp.61-77
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• 2024

The purpose of this study was to develop a method for rapidly diagnosing urban thermal comfort using Unmanned Aerial Vehicle (UAV) based data. The research was conducted at Changwon National University's College of Engineering site and Yongji Park, both located in Changwon, Gyeongsangnam-do. Baseline data were collected using field measurements and UAVs. Specifically, the study calculated field measurement-based thermal comfort indices PET and UTCI, and used UAVs to create and analyze vegetation index (NDVI), sky view factor (SVF), and land surface temperature (LST) images. The results showed that UAV-predicted PET and UTCI had high correlations of 0.662 and 0.721, respectively, within a 1% significance level. The explanatory power of the prediction model was 43.8% for PET and 52.6% for UTCI, with RMSE values of 6.32℃ for PET and 3.16℃ for UTCI, indicating that UTCI is more suitable for UAV-based thermal comfort evaluation. The developed method offers significant time-saving advantages over traditional approaches and can be utilized for real-time urban thermal comfort assessment and mitigation planning

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.45 no.1
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• pp.79-84
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• 2017

This study suggests the ways of improving the training and licensing system of unmanned aerial vehicles (UAVs), which are drawing attention as a future growth industry, through interviews with domestic experts and examples from advanced countries. In order to improve the system, it was suggested to establish a clear concept about unmanned aerial vehicle pilot, to implement a system to obtain and maintain the UAV pilot license, to develop and supply standard textbooks for acquiring certification, and to prepare certification standards for flight simulators.

• ETRI Journal
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• v.28 no.6
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• pp.796-798
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• 2006

This letter proposes a tapered stacked microstrip antenna for application in small unmanned aerial vehicles (UAVs), which has advantages in mountainous terrains. With its tapered structure and increased bandwidth designed to operate at the resonance frequency of 2.4 GHz, the proposed antenna improves directivity, accuracy, and precision of small UAVs. The test flight results show the proposed tapered antenna has a three times higher impedance capability of 350 MHz based on VSWR<2. The transmission pattern is also more reliable than that of previous antenna designs.

• Journal of Advanced Marine Engineering and Technology
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• v.40 no.9
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• pp.830-835
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• 2016

With the relaxation of regulations on unmanned aerial vehicles (UAVs) in the USA, the development of related industries is expected. Hence, it is anticipated that the number the UAVs will reach approximately 600,000 in the USA in 2017. However, automated flights of commercial UAVs are restricted owing to concerns about accidents. To deal with the possibility of collisions, several studies on collision prevention and the routing of UAVs have been conducted. However, these studies do not deal with various situations dynamically or provide efficient solutions. Therefore, we propose a centralized routing method for the UAV that uses vehicular networks. In the proposed scheme, vehicular networks regard UAVs as data packets to be routed. Accordingly, the proposed method reduces UAV processing power required for route searches. In addition, the routing efficiency for UAV flight paths can be improved since congestion can be minimized by using a vehicular network.