• Journal of the Korean Society of Marine Environment & Safety
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• v.28 no.7
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• pp.1129-1139
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• 2022

Collision accidents happen frequently. The majority of ships involved in collisions in the coastal areas of Korea are middle and small size ships. The proportion of collision accidents is only 9% of all types of marine accidents; however, the number of casualties resulting from collisions is 34.4% of all human life damages. Generally, as reported by the people involved in these collisions, the navigation lights of the opponent ships were poor and invisible when the accident happened even though the weather and visibility were good. Furthermore, there are many insistences for poor navigation light conditions of the opponent ship in the bay or harbor. Therefore, it is necessary to analyze the present conditions and safety of navigation lights. Therefore, in this study, we examined the rules and books of navigation lights and compared it to that of other transportation systems, such as aircraft, trains, and road vehicles. Furthermore, we analyzed the current marine traf ic circumstances and ship collision accidents that happened in the past 5 years. Additionally, a questionnaire was prepared to gather the opinion of ship experts and secure the objectivity for improvement methods of navigation lights. Finally, methods to improve the navigation lights on ships were devised.

• Journal of Aerospace System Engineering
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• v.17 no.4
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• pp.110-117
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• 2023

In this paper, the optimal placement of the rotary wing's communication and navigation antennas was evaluated by measuring their performance through ground simulations and flight tests. To select the mounting position of the communication and navigation antenna on the helicopter, after considering the shape and characteristics of the airframe, the radiation patterns, coupling analysis, equipment operation profiles, and antenna type analysis were performed for the aircraft-mounted antenna. Based on the analysis results, a procedure for sequentially performing voltage standing wave ratio (VSWR) measurement and antenna pattern test was established through ground and flight tests of the antenna. The systematic performance measurement method and procedure proposed in this paper were verified through ground and flight tests of the Light Armed Helicopter (LAH) system.

• The Korean Journal of Air & Space Law and Policy
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• v.33 no.1
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• pp.227-260
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• 2018

Recently, as the use of drones increases, the risk of drone accidents and third-party property damage is also increasing. In Korea, due to the recent increase in drone use, accidents have been frequently reported in the media. The number of reports from citizens, and military and police calls regarding illegal or inappropriate drone use has also been increasing. Drone operators may be responsible for paying damages to third parties due to drone accidents, and are liable for paying settlements due to illegal video recording. Therefore, it is necessary to study the idea of providing drone insurance, which can mitigate the liability and risk caused by drone accidents. In the US, comprehensive housing insurance covers damages caused by recreational drones around the property. In the UK, when a drone accident occurs, the drone owner or operator bears strict liability. Also, in the UK, drone insurance joining obligation depends on the weight of the drones and their intended use. In Germany, in the event of personal or material damage, drone owner bears strict liability as long as their drone is registered as an aircraft. Germany also requires by law that all drone owners carry liability insurance. In Korea, insurance is required only for "ultra-light aircraft use businesses, airplane rental companies and leisure sports businesses," where the aircraft is "paid for according to the demand of others." Therefore, it can be difficult to file claims for third party damages caused by unmanned aerial vehicles in personal use. Foreign insurance companies are selling drone insurance that covers a variety of damages that can occur during drone accidents. Some insurance companies in Korea also have developed and sell drone insurance. However, the premiums are very high. In addition, drone insurance that addresses specific problems related to drone accidents is also lacking. In order for drone insurance to be viable, it is first necessary to reduce the insurance premiums or rates. In order to trim the excess cost of drone insurance premiums, drone flight data should be accessible to the insurance company, possibly provided by the drone pilot project. Finally, in order to facilitate claims by third parties, it is necessary to study how to establish specific policy language that addresses drone weight, location, and flight frequency.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.5
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• pp.1-6
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• 2020

UAV (Unmanned Aerial Vehicles) are used widely for military purposes because they are more economical than general manned aircraft and satellites, and have easy access to the object. Recently, owing to the development of IT technology, UAV equipped with various sensors have been released, and their use is increasing in a wide range of fields, such as surveying, agriculture, meteorological observation, communication, broadcasting, and sports. An increasing number of studies and attempts have made use of it. On the other hand, existing research was related mostly to photogrammetry, but there has been a lack of analytical research on LiDAR (Light Detection And Ranging). Therefore, this study examined the characteristics of a UAV LiDAR sensor for the application of a geospatial information field. In this study, the performance of commercialized LiDAR sensors, such as the acquisition speed and the number of echoes, was investigated, and data acquisition and analysis were conducted by selecting Surveyor Ultra and VX15 models with similar accuracy and data acquisition distances. As a result, a DSM of each study site was generated for each sensor, and the characteristics of data density, precision, and acquisition of ground data from vegetation areas were presented through comparison. In addition, the UAV LiDAR sensor showed an accuracy of 0.03m ~ 0.05m. Hence, it is necessary to select equipment considering the characteristics of data for effective use. In the future, the use of UAV LiDAR may be suggested if additional data can be obtained and analyzed for various areas, such as urban areas and forest areas.

• Journal of Advanced Navigation Technology
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• v.27 no.4
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• pp.382-390
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• 2023

The Korea market for LUAV (Light Unmanned Aerial Vehicle) weighing less than 150 kg is growing rapidly. As a result, the market for manufacturing and operating LUAV is expanding, and domestic development of parts and finished products is actively taking place. However, the flight control system and onboard software, which are key components of domestic LUAV, are largely dependent on overseas products due to the excessive cost and period required for development. This paper presented a domestic software development and certification procedure using DO-178C, a guideline for aircraft software development, and the Model-based Development method, and conducted a survey of those involved in the development, manufacturing, and certification of LUAV and analyzed the results. In addition, a case study was conducted to apply the software development plan to the helicopter FCC (Flight Control Computer).

• The Journal of the Acoustical Society of Korea
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• v.41 no.6
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• pp.621-628
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• 2022

The most realistic way to reduce noise outside the building, such as road traffic noise and aircraft noise, is to strengthen the sound insulation performance at the sound collecting points such as balconies, windows, and exterior walls of each building. However, in light of the reality that shading devices outside buildings are not yet widely used, there are not many studies on sound insulation performance improvement using external windows and window devices such as louvers and blinds. In particular, external blinds can not only block the inflow of strong sunlight in the morning and evening from the outside of the building, but also target the sound insulation effect that blocks the peak noise that occurs during commuting hours. In this study, a study was conducted to improve sound insulation performance against external noise by using an external electric blind (EEB), which is one of the most efficient window and door external shading devices. Various sound insulation performance tests were conducted while changing the configuration of external electric blinds developed for light blocking purposes. Through this, it was verified that an additional sound insulation performance of 6 dB can be obtained by installing an external electric blind compared to the reduction performance of general windows.

• The Korean Journal of Air & Space Law and Policy
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• v.29 no.2
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• pp.109-134
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• 2014

Regulation (EC) No 261/2004 of the European Parliament and of the Council of 11 February 2004 establishing common rules on compensation of assistance to passengers in the event of denied boarding and of cancellation or long delay of flights (Regulation No 261/2004) provides extra protection to air passengers in circumstances of denied boarding, cancellation and long-delay. The Regulation intends to provide a high level of protection to air passengers by imposing obligations on air carriers and, at the same time, offering extensive rights to air passengers. If denied boarding, cancellation and long-delay are caused by reasons other than extraordinary circumstances, passengers are entitled for compensation under Article 7 of Regulation No 261/2004. In Wallentin-Hermann v Alitalia-Linee Aeree Italiane SpA(Case C-549/07, [2008] ECR I-11061), the Court did, however, emphasize that this does not mean that it is never possible for technical problems to constitute extraordinary circumstances. It cited specific examples of where: an aircraft manufacturer or competent authority revealed that there was a hidden manufacturing defect on an aircraft which impacts on safety; or damage was caused to an aircraft as a result of an act of sabotage or terrorism. Such events are not inherent in the normal exercise of the activity of the air carrier concerned and is beyond the actual control of that carrier on account of its nature or origin. One further point arising out of the court's decision is worth mentioning. It is not just necessary to satisfy the extraordinary circumstances test for the airline to be excused from paying compensation. It must also show that the circumstances could not have been avoided even if all reasonable measures had been taken. It is clear from the language of the Court's decision that this is a tough test to meet: the airline will have to establish that, even if it had deployed all its resources in terms of staff or equipment and the financial means at its disposal, it would clearly not have been able - unless it had made intolerable sacrifices in the light of the capacities of its undertaking at the relevant time - to prevent the extraordinary circumstances with which it was confronted from leading to the cancellation of the flight.

• The Korean Journal of Air & Space Law and Policy
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• v.1
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• pp.47-85
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• 1989

The Fundamental purpose of the Warsaw Convention was to establish uniform rules applicable to international air transportation. The emphasis on the benefits of uniformity was considered important in the beginning and continues to be important to the present. If the desire for uniformity is indeed the mortar which holds the Warsaw system together then it should be possible to agree on a worldwide liability limit. This liability limit would not be so unreasonable, that it would be impossible for nations to adhere to it. It would preclude any national supplemental compensation plan or Montreal Agreement type of requirement in any jurisdiction. The differentiation of liability limits by national requirement seems to be what is occurring. There is a plethora of mandated limits and Montreal Agreement type 'voluntary' limits. It is becoming difficult to find more than a few major States where an unmodified Warsaw Convention or Hague Protocol limitation is still in effect. If this is the real world in the 1980's, then let the treaty so reflect it. Upon reviewing the Warsaw Convention, its history and the several attempts to amend it, strengths become apparent. Hijackings of international flights have given rise to a number of lawsuits by passengers to recover damages for injuries suffered. This comment is concerned with the liability of an airline for injuries to its passengers resulting from aviation terrorism. In addition, analysis is focused on current airline security measures, particularly the pre-boarding screening system, and the duty of air carriers to prevent weapons from penetrating that system. An airline has a duty to exercise a high degree of care to protect its passengers from the threat of aviation terrorism. This duty would seemingly require the airline to exercise a high degree of care to prevent any passenger from smuggling a weapon or explosive device aboard its aircraft. In the case an unarmed hijacker who boards having no instrument in his possession with which to promote the hoax, a plaintiff-passenger would be hard-pressed to show that the airline was negligent in screening the hijacker prior to boarding. In light of the airline's duty to exercise a high degree of care to provide for the safety of all the passengers on board, an acquiescene to a hijacker's demands on the part of the air carrier could constitute a breach of duty only when it is clearly shown that the carrier's employees knew or plainly should have known that the hijacker was unarmed. A finding of willful misconduct on the part of an air carrier, which is a prerequisite to imposing unlimited liability, remains a question to be determined by a jury using the definition or standard of willful misconduct prevailing in the jurisdiction of the forum court. Through the willful misconduct provision of the Warsaw Convention, air carrier face the possibility of unlimited liability for failure to implement proper preventive precautions against terrorist. Courts, therefore, should broadly construe the willful misconduct provision of the Warsaw Convention in order to find unlimited liability for passenger injuries whenever air carrier security precautions are lacking. In this way, the courts can help ensure air carrier safety and prevention against terrorist attack. Air carriers, therefore, would have an incentive to increase, impose and maintain security precautions designed to thwart such potential terrorist attacks as in the case of Korean Air Lines Flight No.858 incident having a tremendous impact on the civil aviation community. The crash of a commercial airliner, with the attending tragic loss of life and massive destruction of property, always gives rise to shock and indignation. The general opinion is that the legal system could be sufficient, provided that the political will is there to use and apply it effectively. All agreed that the main responsibility for security has to be borne by the governments. I would like to remind all passengers that every discovery of the human spirit may be used for opposite ends; thus, aircraft can be used for air travel but also as targets of terrorism. A state that supports aviation terrorism is responsible for violation of International Aviation Law. Generally speaking, terrorism is a violation of international law. It violates the soverign rights of the states, and the human rights of the individuals. I think that aviation terrorism as becoming an ever more serious issue, has to be solved by internationally agreed and closely co-ordinated measures. We have to contribute more to the creation of a general consensus amongst all states about the need to combat the threat of aviation terrorism.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.19 no.2 s.72
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• pp.195-202
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• 2006

Thin-walled structures are efficiently utilized an automobiles, aircraft, satellite and ship as well as needed light weight simultaneously. This paper presents new shape of automobile hood reinforcement that rotating parts as engine, transmission are protected by thin-walled structures. The automobile hood is concerned about the resonance occurs due to the frequency of the rotating parts. The hood must be designed by supporting the stiffness of design loads and considering the natural frequencies. Hence, it is sustained the stiffness and considered the vibration by resonance. It is deep related to ride. Therefore, the topology, shape and size optimization methods are used to design the automobile hood. Topology technique is applied to determine the layout of a structural component optimum size with maximized natural frequency by volume reduction. In this research, The optimal structure layout of an inner reinforcement of an automobile hood for the natural frequency of a designated mode is obtained by using topology optimization method. The optimum size and the optimum shape are determined by PLBA(Pshenichny-Lim-Belegundu-Arora) algorithm.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.10
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• pp.688-695
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• 2017

Compared to metal, CFRP has excellent mechanical characteristics in terms of intensity, hardness, and heat resistance as well as its light weight that it is used widely in various fields. Therefore, this material has been used recently in the aerospace field. On the other hand, the material has shortcomings in terms of its extreme vulnerability to damage occurring internally from an external impact. This study examined the intensity up to its destruction from repeated use with the internal impact of a CFRP laminated plate that had also been exposed to external impact obtain design data for the external plate of aircraft used in the aerospace field. For the experimental method, regarding the quasi-isotopic type CFRP specimen and orthotropic CFRP specimen that are produced with a different layer structure, steel spheres with a diameter of 5 mm were collided to observe the resulting impact damage. Through a 3-point flexural fatigue experiment, the progress of internal layer separation and impact damage was observed. Measurements of the flexural fatigue strength after the flexural fatigue experiment until internal damage occurs and the surface impacted by the steel spheres revealed the quasi-isotopic layer structure to have a higher intensity for both cases.