• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.40 no.8
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• pp.678-687
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• 2012

The Fly-By-Wire(FBW) flight control system is essential to improve the stability and flying quality of the helicopter. Advanced aerospace companies, such as Bell-Sikorsky (USA) and NHI (European Consortium), have already applied the FBW flight control system to manufacture V-22 and NH-90 helicopters, respectively. This paper addresses the development of control law design using model inversion method improve the hover and low speed handling qualities of helicopter based on BO-105 model in 'Day' and 'Degraded visual environments(DVEs)' in accordance with ADS-33E-PRF. Design parameters are optimized to satisfy the handling qualities specification using Control Designer's Unified Interface (CONDUIT) commercial control law software. The result of the analysis based on CONDUIT and non-real time simulation in-house software, HETLAS (HElicopter Trim Linearization And Simulation) reveals that the provides an efficient mean to achieve Level 1 handling qualities.

• Journal of Ginseng Research
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• v.41 no.1
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• pp.10-22
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• 2017

Background: Asian ginseng and American ginseng are functional foods that share a close genetic relationship and are well-known worldwide. This article aims to investigate the correlation between morphological characteristics and the inherent quality of Asian and American ginsengs. Methods: In this study, an ultra-HPLC-quadrupole/time-of-flight MS (UHPLC-Q/TOF-MS) method was established for the quantitative analysis of 45 ginseng samples. The method developed for determination was precise and accurate. Results: The results showed that Asian ginseng samples with the same growing time (with the same or similar number of stem scars) that had a thinner main root, a longer rhizome and more branch roots contained greater amounts of ginsenosides. For American ginseng, two tendencies were observed in the relationship between the diameter of the main root and contents of ginsenosides. One tendency was that samples with thinner main roots tended to contain higher levels of ginsenosides, which was observed in the samples sold under the commercial name pao-shen. Another tendency was that samples with thicker main roots contained higher contents of ginsenosides, which was observed in the samples sold under the commercial name pao-mian, as well as in samples of American ginseng cultivated in Jilin, China. Conclusion: An approach using ultra-HPLC-quadrupole/time-of-flight MS was successfully established to link morphology and active components for evaluating the quality of Asian and American ginsengs. Clear correlation between visible morphological features and quality of Asian and American ginsengs was found. People can see the difference; this means consumers and vendors can evaluate ginseng by themselves.

• Journal of the Korean Society for Aviation and Aeronautics
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• v.25 no.3
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• pp.61-67
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• 2017

The Nose Landing Gear(NLG) of Rotary Wing Aircraft is an essential equipment in Landing System for pilot to perform a flight mission. It supports the fuselage at ground and absorbs the impact from the ground when landing, thereby, these functions sustain operational capability for pilot and crew. However, the A aircraft caused stick-slip behavior when it was stationed on the ground. Therefore, this paper summarizes pilot comment in operation which are classified by cause of occurrence and the troubleshooting process about each comment. It also describes design improvements which was derived from troubleshooting and suggests verification results of flight test.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.41 no.1
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• pp.61-69
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• 2013

In an evaluation process of aircraft flying qualities, a clear and concise application interface is important since an evaluation process requires numerous repeated evaluation. This flight evaluation program have implemented efficient flight evaluation user interface along with changed trim condition interface and composed of comprehensive evaluation interface have mounted all automated FQ evaluation modules that was selected to be compose of 14 items in respect of an unmanned fixed-wing aircraft. Accordingly when it is necessary to design the flight control system as well as to develop a FQ considered aircraft, this S/W can be utilized as a tool that is a useful test evaluation S/W with scalability and enable to reduce the time and the cost of verification and evaluation process.

• Journal of the Korean Society of Industry Convergence
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• v.26 no.5
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• pp.775-784
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• 2023

Drone images are being used more and more actively in the fields of surveying and spatial information, and are rapidly replacing existing aerial and satellite images. The technology of quickly acquiring real-time data at low cost and processing it is now being applied to actual industries beyond research. However, there are also problems encountered as this progresses. When high-resolution spatial information is acquired using a general 2D flight plan for a terrain with sever undulations, problems arise due to the difference in resolution of the data. In particular, when a low-altitude high-resolution image is taken using a drone in a mountainous or steep terrain, there may be a problem in image matching due to a resolution difference caused by terrain undulations. This problem occurs because a drone acquires data while flying on a 2D plane at a fixed altitude, just like conventional aerial photography. In order to acquire high-quality 3D data using a drone, the scale difference for the shooting distance should be considered. In addition, in order to obtain facade images of large structures, it is necessary to take images in 3D space. In this study, in order to improve the disadvantages of the 2D flight method, a 3D flight plan was established for the study area, and it was confirmed that high-quality 3D spatial information could be obtained in this way.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.42 no.8
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• pp.707-712
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• 2014

Aircraft fuel indicator is a device to indicate the amount of fuel remained during flight, where accurate and consistent operation of the indicator should be maintained. Previously the Korean Utility Helicopter fuel indicator sporadically displayed abnormal sign by "8888" during flight, jeopardizing flight safety. Inappropriate EMI/EMC performance was detected during trouble shooting process. The cause of the abnormal display was found to be resulted from unstable power induced by electro-magnetic disturbance and CAN communication error. The aircraft fuel indicator design was improved and the design compatibility was verified to avoid abnormal display.

• Journal of Advanced Navigation Technology
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• v.19 no.5
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• pp.370-378
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• 2015

The data acquisition unit, signal acquiring and processing equipment, processes and provides major data of an aircraft such as engine system, power train system, hydraulic system, etc. However, it had lots of failure related to the system during production test flight, and it is necessary to fix them perfectly as soon as possible because of the significance of the equipment. In this paper, it contains failure classification and analysis for each defect element to improve whole software as well as electrical circuit. Particularly, utilizing Fault Injection Method based interworking test, more efficient improvement activity was performed for not only equipment level but also aircraft level, and as a result, it is achieved that considerable betterment of Surion quality and flight safety.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.42 no.1
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• pp.76-81
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• 2014

Military helicopter is exposed to the enemy gun firing due to the low altitude flight of contour flight, hovering & nap of the Earth flight, therefore it has the high possibility to be exploded by the gun firing. Recently the Anti-ballistic requirement is required to get the high level of safety from gun firing in required operational capability. The first military utility helicopter of SURION has the Anti-ballistic requirement and explosion proof. In order to meet the requirement, OBIGGS is adopted for the first time in KUH. It is proven that Anti-Explosion capability is satisfied to requirement for improving vent system which was insufficiently designed in development period and related to Anti-explosion.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.41 no.12
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• pp.1002-1010
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• 2013

Intercom System(ICS) of Korean Utility Helicopter(KUH) is an essential equipment for pilot to perform flight mission and it consists of communication system of KUH with VHF-FM radio set and U/VHF-AM radio set. It provides pilots and crews with internal communication, external communication and audible alarm. It has function of controlling volume and selecting two communication modes, normal mode and backup mode. This paper summarizes pilot comments in flight test which are classified by cause of occurrence and the troubleshooting process about each comment. It also describes design improvements which was derived from troubleshooting and suggests verification results of flight test.

• Journal of Korean Society for Quality Management
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• v.47 no.3
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• pp.467-478
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• 2019

Purpose: The purpose of this paper is to improve quality for water infiltration to FCISA during military aircraft operation. Methods: A series of troubleshooting studies were conducted to identify the root cause of the water infiltration and reproduce the defects through various simulation tests. And design improvement measures were derived, and countermeasures were taken to prevent recurrence of moisture inflow defects. Conclusion: FCISA operates a very important role in the operation of military aircraft, and defects due to water infiltration are very fatal to flight safety. In this study, the root cause was identified and the design improvement to prevent recurrence was carried out through the failure investigation performed in this study, and the FCISA was improved so that the flight safety was not affected. The results of this study will be valuable back data that can be reflected in the design process through Lessons-Learned in the design phase of the aircraft that will be developed in the future.