• Journal of Powder Materials
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• v.30 no.2
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• pp.140-145
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• 2023

Although the Ti-6Al-4V alloy has been used in the aircraft industry owing to its excellent mechanical properties and low density, the low formability of the alloy hinders broadening its applications. Recently, laser-powder bed fusion (L-PBF) has become a novel process for overcoming the limitations of the alloy (i.e., low formability), owing to the high degree of design freedom for the geometry of products having outstanding performance used in high-tech applications. In this study, to investigate the effect of bulk shape on the microstructure and mechanical properties of L-PBFed Ti-6Al-4V alloys, two types of samples are fabricated using L-PBF: thick and thin samples. The thick sample exhibits lower strength and higher ductility than the thin sample owing to the larger grain size and lower residual dislocation density of the thick sample because of the heat input during the L-PBF process.

• Asia-pacific Journal of Multimedia Services Convergent with Art, Humanities, and Sociology
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• v.6 no.8
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• pp.577-584
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• 2016

UAV(Unmaned Aerial Vehicle), which is autonomous flight without pilots. Recently, UAV is being applied to various fields such as video recording, aerial photogrammetry. In particular, UAV is getting a lot of attention in the field of space-related information because of it's data acquisition speed and economic feasibility. But analytical study of an unmanned air-side technologies are lacking. In this study, the research of equipment for the unmanned aerial surveys and UAV technologies and trend analysis for generation of terrain model and ortho image effectively were performed. As a result, the ways to improve the utilization field of unmanned aerial surveying and processing of fixed-wing and rotary-wing unmanned aircraft. were suggested. If analytical research on generation of terrain models and ortho image will be performed, production efficiency of the geospatial information industry is expected to be significantly increased.

• Journal of Advanced Navigation Technology
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• v.26 no.6
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• pp.528-535
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• 2022

Although the domestic aviation industry has made rapid progress with the development of aircraft manufacturing and transportation technologies, aviation safety accidents continue to occur. The supervisory agency classifies hazards and risks based on risk-based aviation safety data, identifies safety trends for each air transportation operator, and conducts pre-inspections to prevent event and accidents. However, the human classification of data described in natural language format results in different results depending on knowledge, experience, and propensity, and it takes a considerable amount of time to understand and classify the meaning of the content. Therefore, in this journal, the fine-tuned KoBERT model was machine-learned over 5,000 data to predict the classification value of new data, showing 79.2% accuracy. In addition, some of the same result prediction and failed data for similar events were errors caused by human.

• Journal of Advanced Navigation Technology
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• v.26 no.6
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• pp.380-392
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• 2022

In this paper, the new vertiport regulations of the FAA and EASA are analyzed for urban air mobility(UAM), and the major components of the vertipad and the new specifications of each component are analyzed, and UAM operation in various environments is analyzed. Additional components for vertiport and regulations for surrounding airspace were also reviewed. Afterwards, based on the size of the S-A1 aircraft being developed by Hyundai Motors, domestic vertiport specifications and layouts were investigated for UAM operation, and these were applied to the city of Incheon. In addition, the time required for using a taxi or car were compared with the time required for using UAM between major locations in Incheon and Seoul.

• Journal of Advanced Navigation Technology
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• v.28 no.3
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• pp.338-347
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• 2024

This paper deals with the study of bird collision avoidance measures in UAM operations from an operator's perspective. Urban air traffic is defined as a next-generation transportation system that uses environmentally friendly electric vertical take-off and landing (eVTOL) aircraft to provide transportation services between key points within and around urban centers. For the successful establishment of the UAM industry, it is necessary to ensure safety issues that determine public acceptance. Among the hazards that can occur in aviation operations, preventing bird collisions in urban environments is a measure that can greatly secure operational safety and public acceptance. In addition to physical measures, procedural control measures are required to prevent bird strikes. In order to ensure the safety of UAM operations, this study aims to provide a direction for the establishment of UAM bird collision prevention measures by categorizing bird collision prevention measures into physical and procedural methods and flight sections such as takeoff, landing, and corridor sections. Through this, we hope to contribute to the improvement of the safety of the urban air traffic operation system.

• Journal of the Institute of Convergence Signal Processing
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• v.24 no.4
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• pp.241-248
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• 2023

Despite the recent short history of drones, the applying field of drones has been used for various purposes in a wide variety of areas and fields. As such, with the emergence of various types of drones over the years, in a broad sense, a remote controlled mobile object that can be controlled by wired and wireless control may be a suitable definition for drone because of various types of drones in recent years. This paper aims to help readers who want to research, develop, and use drones by examining the history, application fields, and future prospects of drones, including Unmanned Surface Vehicle(USV) and Unmanned Underwater Vehicles(UUV), as well as aerial type drones. Through this paper, it is expected that these drones will continue to be used in various fields in the future, and the prospect of future development will continue constantly. However, for the development of domestic drone technology and industry, the government's improvement in drone-related regulations should be supported.

• The Korean Journal of Air & Space Law and Policy
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• v.23 no.2
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• pp.3-29
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• 2008

The volume of air passengers and cargo transportation has increased rapidly in recent years. This trend will be even more noticeable as the high-tech service industry expands and the globalization progresses. In an effort to reflect and to cope with this trend, many conventions concerning international air transportation have been concluded. The Republic of Korea has also acceded to the Montreal Convention of 1999 on September 20th, 2007 which became effective on December 29th 2007. However, Korea currently does not provide any private law on the liability of domestic air carrier, leaving the regulation wholly to the general conditions of carriage of private air lines. These general conditions of carriage, however, are not sufficient to regulate the liabilities of domestic air carriers, because they cannot be fully recognized as a legitimate source of law applicable in the court. This situation is inconvenient for both air carrier and their customers. Thus, the Ministry of Justice of Korea has decided to enact a law that will regulate domestic air transportation, namely, "Domestic Carriage by Air Act", as a part of the Korean Commercial Code. So was composed a special committee for legislation of the Domestic Carriage by Air Act. This writer has led the committee as a chairman. The committee has held in total 10 meetings so far and has completed a draft bill for the part VI of the Korean Commercial Code, "Air Carriage." The essentials of the draft are as follows: First, the establishment of Part VI in the Commercial Code. The Korean Commercial Code already includes a series of provisions on road transportation in part II and carriage by sea in part V. In addition to these rules regulating different types of transportation, the Domestic Carriage by Air Act will newly establish part VI to regulate air carriages. Eventually, the Commercial Code will provide an integrated legal system on the transportation industry. Second, the acceptance of the basic liability system which major international conventions, such as Montreal Convention of 1999 and Guadalajara Convention of 1961, have adopted. This is very important, because the law of air carriage is unified worldwide through various international conventions, making it necessary and significant for the new act to achieve conformity between rules of international air carriage and that of domestic air carriage. Third, the acceptance of Rome Convention system on damage caused by foreign aircraft to third parties on the surface. Fourth, the application of rules on domestic road carriage or carriage by sea mutatis mutandis with necessary modifications. This very point is the merit of inserting domestic air transportation law into the Commercial Code. By doing so, the number of articles can be reduced and the rules on air carriage can conform to that of road transportation and carriage by sea. The bill is expected to be passed by the parliament at the end of this year and is expected to be effective by end of July 2009.

• Journal of Convergence for Information Technology
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• v.7 no.3
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• pp.27-36
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• 2017

In almost industries, such as the logistics industry, marine fisheries, agriculture, industry, and services, small unmanned aerial vehicles are used for aerial photographing or closing flight in areas where human access is difficult or CCTV is not installed. Also, based on the information of small unmanned aerial photographing, application research is actively carried out to efficiently perform surveillance, control, or management. In order to carry out tasks in a mission-based manner in which the set tasks are assigned and the tasks are automatically performed, the small unmanned aerial vehicles must not only fly steadily but also be able to charge the energy periodically, In addition, the unmanned aircraft need to land automatically and precisely at certain points after the end of the mission. In order to accomplish this, an automatic precision landing method that leads landing by continuously detecting and recognizing a marker located at a landing point from a video shot of a small UAV is required. In this paper, it is shown that accurate and stable automatic landing is possible even if simple template matching technique is applied without using various recognition methods that require high specification in using low cost general purpose small unmanned aerial vehicle. Through simulation and actual experiments, the results show that the proposed method will be made good use of industrial fields.

• Proceedings of the Korean Society of Laser Processing Conference
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• 1998.11a
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• pp.0-0
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• 1998

-Part I- As market needs become more various, the production of smaller quantities of a wider variety of products becomes increasingly important. In addition, in order to meet demands for more efficient production, long-term unmanned factory operation is prevailing at a remarkable pace. Within this context, laser machines are gaining increasing popularity for use in applications such as cutting and welding metallic and ceramic materials. FANUC supplies four models of $CO_2$ laser oscillators with laser power ranging from 1.5㎾ to 6㎾ on an OEM basis to machine tool builders. However, FANUC has been requested to produce laser oscillators that allow more compact and lower-cost laser machines to be built. To meet such demands, FANUC has developed six models of Slab type YAG laser oscillators with output power ranging from 150W to 2㎾. These oscillators are designed mainly fur cutting and welding sheet metals. The oscillator has an exceptionally superior laser beam quality compared to conventional YAG laser oscillators, thus providing significantly improved machining capability. In addition, the laser beam of the oscillator can be efficiently transmitted through quartz optical fibers, enabling laser machines to be simplified and made more compact. This paper introduces the features of FANUC’s developed Slab type YAG laser oscillators and their applications. - Part II - All-solid-state lasers employing laser diodes (LD) as a source of pumping solid-state laser feature high efficiency, compactness, and high reliability. Thus, they are expected to provide a new generation of processing tools in various fields, especially in automobile and aircraft industries where great hopes are being placed on laser welding technology for steel plates and aluminum materials for which a significant growth in demand is expected. Also, in power plants, it is hoped that reliability and safety will be improved by using the laser welding technology. As in the above, the advent of high-power all-solid-state lasers may not only bring a great technological innovation to existing industry, but also create new industry. This is the background for this project, which has set its sights on the development of high-power, all-solid-state lasers with an average output of over 10㎾, an oscillation efficiency of over 20%, and a laser head volume of below 0.05㎥. FANUC Ltd. is responsible for the research and development of slab type lasers, and TOSHIBA Corp. far rod type lasers. By pumping slab type Nd: YAG crystal and by using quasi-continuous wave (QCW) type LD stacks, FANUC has already obtained an average output power of 1.7㎾, an optical conversion efficiency of 42%, and an electro-optical conversion efficiency of 16%. These conversion efficiencies are the best results the world has ever seen in the field of high-power all-solid-state lasers. TOSHIBA Corp. has also obtained an output power of 1.2㎾, an optical conversion efficiency of 30％, and an electro-optical conversion efficiency of 12%, by pumping the rod type Nd: YAG crystal by continuous wave (CW) type LD stacks. The laser power achieved by TOSHIBA Corp. is also a new world record in the field of rod type all-solid-state lasers. This report provides details of the above results and some information on future development plans.

• Journal of Korea Entertainment Industry Association
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• v.15 no.4
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• pp.349-357
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• 2021

Recently, drones are rapidly becoming common and expanding. There is a great need for diversity in whether drone flight data can be used as entertainment technology analysis data. In particular, it is necessary to check whether it is possible to analyze and utilize the flight and operation process of entertainment drones, which are developing through autonomous and intelligent methods, through data analysis and machine learning. In this paper, it was confirmed whether it can be used as a machine learning technology by using FC data in the evaluation of drones for entertainment. As a result, FC data from DJI and Parrot such as Mavic2 and Anafi were unable to analyze machine learning for entertainment. It is because data is collected at intervals of 0.1 second or more, so that it is impossible to find correlation with other data with GCS. On the other hand, it was found that machine learning technologies can be applied in the case of Fixhawk, which used an ARM processor and operates with the Nuttx OS. In the future, it is necessary to develop technologies capable of analyzing the characteristics of entertainment by dividing fixed-wing and rotary-wing flight information. For this, a model shoud be developed, and systematic big data collection and research should be conducted.