• Journal of Hydrogen and New Energy
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• v.29 no.6
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• pp.587-595
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• 2018

Recently, research is being conducted to use a fuel cell as a power source of unmanned aircraft. However, safety standards about applying fuel cells to unmanned aircraft are insufficient. In this paper, to improve the safety of the fuel cells for unmanned aircraft is experimentally studied. For this reason, standards for safety of fuel cells were analyzed. And influence of vibration among the evaluation items related to the safety of the fuel cell for unmanned aircraft was discussed. In order to, at constant intervals, vibration was applied to the fuel cell, then the performance was measured, the measurement items were gas tightness, polarization curve, frequency response analysis (FRA). A total of 220 hours was experimented at 20 hour intervals. the result of vibration test, gas leakage rate was a maximum of -0.04826 kPa/min and Polarization curve reached a maximum of 1.0103 times of the initial value, the charge transfer resistance reached a maximum of 1.0104 times of the initial value. This research indicate that performance of fuel cell is affected by vibration and this study is expected to contribute to the safety of fuel cell for unmanned aircraft.

• Journal of Korea Multimedia Society
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• v.20 no.3
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• pp.437-445
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• 2017

Necessity of security reinforcement has been increased these days. As a result, surveillance systems using CCTV and the patrol system by person have been applied to security zone. However, CCTV has a blind spot and CCTV itself cannot handle emergency situation. Patrol system by person is economically expensive. To overcome these disadvantages, this paper presents an image-based surveillance system using unmanned aircraft. As a default, unmanned aircraft traces lines installed on ground which represents path for patrolling. If the aircraft detects objects, then it keeps a constant distance between object without missing the object in the image. Simulation results show that the proposed system can be operated even with unmanned aircraft with low specification.

• Electronics and Telecommunications Trends
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• v.33 no.3
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• pp.70-77
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• 2018

Considering the increased demand for unmanned aircraft systems (UASs) in various commercial and public sectors, it is necessary to integrate a UAS into a national airspace program for manned aircraft operations. For the safe operation of a UAS in a national airspace program, in addition to the detection and avoidance capability at a similar level of "see and avoid" by pilots of manned aircraft, a highly reliable control and non-payload communication (CNPC) link is needed for unmanned aircraft vehicle (UAV) control at a similar level as aircraft control by manned aircraft pilots. In this paper, we analyze the trends in domestic and international standardization activities on the UAS CNPC network technology for the safe integration of UAS into a national airspace program.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.45 no.1
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• pp.10-19
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• 2022

Recently, the Defense Advanced Research Projects Agency(DARPA) in the United States is studying a new concept of war called Mosaic Warfare, and MUM-T(Manned-Unmanned Teaming) through the division of missions between expensive manned and inexpensive unmanned aircraft is at the center. This study began with the aim of deriving the priority of autonomous functions according to the role of unmanned aerial vehicles in the present and present collaboration that is emerging along with the concept of mosaic warfare. The autonomous function of unmanned aerial vehicles between the presence and absence collaboration may vary in priority depending on the tactical operation of unmanned aerial vehicles, such as air-to-air, air-to-ground, and surveillance and reconnaissance. In this paper, ACE (Air Combat Evaluation), Skyborg, and Longshot, which are recently studied by DARPA, derive the priority of autonomous functions according to air-to-air collaboration, and use AHP analysis. The results of this study are meaningful in that it is possible to recognize the priorities of autonomous functions necessary for unmanned aircraft in order to develop unmanned aerial vehicles according to the priority of autonomous functions and to construct a roadmap for technology implementation. Furthermore, it is believed that the mass production and utilization of unmanned air vehicles will increase if one unmanned air vehicle platform with only essential functions necessary for air-to-air, air-to-air, and surveillance is developed and autonomous functions are expanded in the form of modules according to the tactical operation concept.

• Journal of Aerospace System Engineering
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• v.15 no.4
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• pp.64-74
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• 2021

Unmanned Aircraft Systems (UAS) are rapidly emerging not only as a key military power, such as surveillance and reconnaissance for military purposes but also as a new air transportation means in the form of Urban Air Mobility (UAM). Currently, airworthiness certification is carried out focused on the verification of technical standards for flight safety suitability of aircraft design in accordance with the Military Aircraft Flight Safety Certification Act and does not employ the model for operational risk assessment for mission areas and airspace. In this study, in order to evaluate the risk of the mission area from the perspective of the UAS operator, a risk assessment simulation has been conducted by applying the Specific Operations Risk Assessment (SORA) model to the operating environment of the Korean military UAS. Also, the validity of the SORA model has been verified through the analysis of simulation results, and a new application plan for airworthiness certification of the military unmanned aerial system has been presented.

• International journal of advanced smart convergence
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• v.9 no.3
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• pp.207-214
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• 2020

Currently, the operation of unmanned aerial vehicle (UAV) is regulated to be able to fly only within the visible range, but in recent years, the needs for operation in the invisible area, in the urban area and at night have increased. In order to operate UAVs in the invisible area, at night, and in the urban area, a flight path for UAVs must be prepared like those operated by manned aircraft, and for this, it is necessary to establish an unmanned aircraft system traffic management (UTM). In order to establish the UTM, information on the minimum separation distance to prevent collisions with UAVs and buildings is required, and accordingly, information on the navigation performance of UAVs is required. In order to analyze the navigation performance of an UAV, total system error (TSE), which is the difference between the planned flight path and the actual location of the UAV, is required. If the collected data are insufficient and classification according to integrity, independence, and direction is not performed, accurate navigation performance is not derived. In this paper, propose a navigation performance analysis method of UAV that is derived TSE using flight data and modeled with normal distribution, analyze performance.

• Journal of the Korea Institute of Military Science and Technology
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• v.19 no.5
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• pp.654-661
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• 2016

An unmanned aircraft refers to an aircraft which carries no human pilot and is operated under remote control or in autonomous operational mode. An unmanned aircraft system consist of a one system which include UAV(s), UAV control station and data link, etc. As the UAVs can perform the dull, dangerous and difficult missions, various kinds of UAVs with different sizes and weights have been developed and operated for both civil and military areas. It is important to develop the airworthiness certification criteria of the UAVs to minimize the risks of fatal impacts on human life and environment and to achieve the equivalent level of safety to the manned aircraft. Analysis of the KAS Part 23 and STANAG 4671 can provide guidelines for the generation of the airworthiness certification criteria for the UAVs in civil application.

• Journal of Advanced Marine Engineering and Technology
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• v.37 no.7
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• pp.737-742
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• 2013

Recently, unmanned aircrafts for safe measurement in hazardous locations have been developed. In a method of operation of unmanned aircraft vehicles (UAV), there are two methods of manual control and automatic control. Small UAVs are used for low altitude surveillance flights where unknown obstacles can be encountered. Obstacle avoidance is one of the most challenging tasks which the UAV has to perform with high level of accuracy. In this study, we used a laser range finder as an obstacle detector in automatic navigation of unmanned aircraft to patrol the destination automatically. We proposed a system to avoid obstacles automatically by measuring the angle and distance of the obstacle using the laser range finder.

• Korean Security Journal
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• no.30
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• pp.61-83
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• 2012

Al-Qaeda follower who planned to attacks the Pentagon and the Assembly by unmanned aircraft equipped with explosives was caught in the dictionary in September 2011. In addition, high-performance unmanned aerial vehicles in the United States 'sentinel' of the technology being leaked to Iran in late 2011 was an accident. Terrorist attacks on the forces used unmanned aircraft will be the day the not too distant. The purpose of this research is to provide response plans against acts of terrorism utilizing unmanned aircrafts to prevent large losses of lives such as the terrorist attacks of September 11. Discussing in detail, this research suggests revising and newly implementing the definition and categorization of unmanned aircrafts as well as relevant punishment in current aeronautics regulations as an initial response against acts of terrorism utilizing unmanned aircrafts. This is in order to newly implement and revise current relevant regulations that inadequately address the rapidly developing and changing unmanned aircrafts which will lead to increased sense of alarm for the potential terrorists, and also to introduce a systematic tool to punish those who commit such acts by clearly establishing the grounds for punishment. Also, under the binary operating system over airspace currently implemented globally, it is impossible to identify and control the infiltration of airspace by unmanned aircrafts. Recognizing such limitations, this research suggests a combined operation of airspace for unmanned and manned aircrafts as a second way of response for acts of terrorism utilizing unmanned aircrafts. A systematic integrated operation of airspace will appropriately control unmanned/ manned aircrafts that were not previously reported or otherwise have deviated from navigation routes, and will be able to prevent terrorism attempts utilizing aircrafts beforehand.

• Journal of Engineering Education Research
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• v.17 no.5
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• pp.17-22
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• 2014

Unmanned aerial vehicles (UAVs) that have been recently commercialized can largely be divided into fixed-wing aircraft and rotor aircraft by their styles and flight characteristics. Although the fixed-wing aircraft represents higher power efficiency, higher speed, longer flight distance and larger loading weight than the rotor aircraft, they have a disadvantage of requiring a space for take-off and landing. On the other hand, the rotor aircraft can implement vertical take-off and landing (VTOL) and represents various flight modes (hovering, steep bank turns and low-speed flights). But they require both precision take-off control and attitude control. In this study, we used a quad-tilt rotor UAV to combine advantages in both the fixed-wing aircraft and the rotor aircraft. The quad-tilt rotor (QTR) system was designed and constructed by adding a tilt device with a servo motor to a general quad-rotor vehicle.