• 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 Advanced Navigation Technology
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• v.27 no.6
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• pp.776-781
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• 2023

K-UAM will be commercialized through maturity after 2035. Since the Urban Air Mobility (UAM) corridor will be used vertically separating the existing helicopter corridor, the corridor usage is expected to increase. Therefore, a system for monitoring corridors is also needed. In recent years, object detection algorithms have developed significantly. Object detection algorithms are largely divided into one-stage model and two-stage model. In real-time detection, the two-stage model is not suitable for being too slow. One-stage models also had problems with accuracy, but they have improved performance through version upgrades. Among them, YOLO-V5 improved small image object detection performance through Mosaic. Therefore, YOLO-V5 is the most suitable algorithm for systems that require real-time monitoring of wide corridors. Therefore, this paper trains YOLO-V5 and analyzes whether it is ultimately suitable for corridor monitoring.K-uam will be commercialized through maturity after 2035.

• Journal of Aerospace System Engineering
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• v.12 no.4
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• pp.49-56
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• 2018

In this paper, the performance analysis and the experiment of the brake system using the small piezoelectric-hydraulic pump were performed. Initially, the 3-D modeling of the brake load components was performed for the construction of the brake system. Subsequently, modeling using the commercial program AMESim was performed. A floating caliper model was used as a load for modeling the brake system. Through the AMESim simulation, load pressure, check valve displacement and flow rate under no load state were calculated, and performance analysis and changes in dynamic characteristics were confirmed by adding brake load. A jig for use in fixing the brake load during performance test was manufactured. The flow rate was assessed under no load condition and load pressure formation experiments were performed and compared with simulation results. Experimental results revealed the maximum load pressure as about 73bar at 130Hz and the maximum flow rate as about 203cc/min at 145Hz, which satisfied the requirement of small- and medium-sized UAV braking system. In addition, simulation results revealed that the load pressure and discharge flow rate were within 6% and 5%, respectively. Apparently, the modeling is expected to be effective for brake performance analysis.

• Current Research on Agriculture and Life Sciences
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• v.8
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• pp.107-113
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• 1990

This study was attempted to develop a remote controllable speed sprayer in order to protect an operator from agricultural chemicals. For the purpose of remote controllable transmission was developed by using one chip microcomputer. The following results could be summarized in this study. 1. Remote controllable transmission developed had not made even a single mistake during the test performed 100 times repeat. Thus, it could that this machine was very accurate. 2. One chip microcomputer was made by machine language and its was with in 3 sec's which was the same as human did. 3. One chip microcomputer which was used in the experiment could be widely used to automation of agricultural machinery, since it is smaller and chiper than any other similar ones such as personal computer, lap tap, one board computer. 4. Since, farm tractor has the same type of transmission as this system, it also could be adapted to farm tractors. 5. In this experiment, transmission lever was remote controll were designed to operate simultaneously. Thus, this system developed was more complicate than conventional system. However, by removing this transmission lever and by mounting the remote controll system at the speed sprayer, it would be higher and easier to handle than the conventional one.

• Geophysics and Geophysical Exploration
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• v.8 no.4
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• pp.270-279
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• 2005

Under the research project supported by Japanese Ministry of Education, Culture, Sports, Science and Technology (MEXT), we have conducted the development of GPR systems for landmine detection. Until 2005, we have finished development of two prototype GPR systems, namely ALIS (Advanced Landmine Imaging System) and SAR-GPR (Synthetic Aperture Radar-Ground Penetrating Radar). ALIS is a novel landmine detection sensor system combined with a metal detector and GPR. This is a hand-held equipment, which has a sensor position tracking system, and can visualize the sensor output in real time. In order to achieve the sensor tracking system, ALIS needs only one CCD camera attached on the sensor handle. The CCD image is superimposed with the GPR and metal detector signal, and the detection and identification of buried targets is quite easy and reliable. Field evaluation test of ALIS was conducted in December 2004 in Afghanistan, and we demonstrated that it can detect buried antipersonnel landmines, and can also discriminate metal fragments from landmines. SAR-GPR (Synthetic Aperture Radar-Ground Penetrating Radar) is a machine mounted sensor system composed of B GPR and a metal detector. The GPR employs an array antenna for advanced signal processing for better subsurface imaging. SAR-GPR combined with synthetic aperture radar algorithm, can suppress clutter and can image buried objects in strongly inhomogeneous material. SAR-GPR is a stepped frequency radar system, whose RF component is a newly developed compact vector network analyzers. The size of the system is 30cm x 30cm x 30 cm, composed from six Vivaldi antennas and three vector network analyzers. The weight of the system is 17 kg, and it can be mounted on a robotic arm on a small unmanned vehicle. The field test of this system was carried out in March 2005 in Japan.

• The Korean Journal of Air & Space Law and Policy
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• v.30 no.2
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• pp.3-36
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• 2015

As of end of 2014, the population engaging in aviation activities for leisure has reached approximately 13 million, where approximately 356 cases involve a general aircraft, 200 cases involve light aircraft, and 636 cases involve an ULM. The industry for leisure has become a very promising industry in line with rapidly rising living standards which are expected to further increase in the future. The demand for such services is expected to increase over time. The purpose of this paper is to review the development and site selection of airfields in anticipation of these developments in the industry. While the government also has experience in the review of airfield location and candidate sites, it is not the government that carries out the actual construction. As such, the feasibility of the site needs to be verified in terms of actual construction. This study identified factors for Site Selection of factors through a review of related documents and existing research reports. A questionnaire was also used to collect the views of experts in the field, which was then analyzed. The Research model was confirmed in the layered form for an AHP analysis. The factors for Site Selection were identified as the technical / operational factors and economic / political elements for a two-stage configuration. The third step consisted of technical and operational elements. The final step is was constructed a total of 11 elements (weather, surface conditions, obstacle limitation surface, airspace conditions, operating procedures, noise problems, environmental issues, availability of facilities, construction and investment costs, contribution to the local economy, accessibility, demand / the proximity of demand). The surveys are conducted for more than 10 General and light aircraft pilots, professionals, and instructor. The analysis results showed a higher level in the technical / operating elements (73.2%) in the first step, while the next step sawa higher level of the operational elements (30.9%) than the other. The factors for Site Selection were any particular elements did not appear high, the weather conditions (17.5%), noise problems (19.8%), the proximity of demand (6%), accessibility (5.7%), environmental issues (11.1%), availability of facilities (8%), airspace conditions (7.9%), obstacle limitation surface (12%), construction and investment costs (4.2%) and to operating procedures (4.9%), contribution to the local economy (3.8%).