• Journal of the Korea Institute of Military Science and Technology
• /
• v.20 no.6
• /
• pp.743-751
• /
• 2017

To evaluate the structural integrity of the helicopter radome, we performed bird strike analysis using SPH (Smoothed Particle Hydrodynamics) technique. Since the SPH method is a meshfree method, there is no phenomenon such as mesh tangling and it is suitable to predict the dispersion behavior of debris and debris cloud generated by high-speed impact. In order to observe the scattering direction of fractured bolts, the analysis were performed under the condition that the fracture occurs at the proof load. As a result of bird strike analysis, there is no secondary damage as well as the damage due to, the dispersion behavior of the bird model, and the scattering of the fractured bolts and radome. From the additional analysis that were performed to determine the actual bolt fracture, only plastic deformation is predicted since the maximum stress of the bolt does not exceed the ultimate stress.

• Journal of the Korean Society for Aeronautical & Space Sciences
• /
• v.37 no.2
• /
• pp.181-186
• /
• 2009

The objective of this study is ensuring safety of cabin when the blade impacts into a obstacle by verifying safety of the rotor mast and the transmission using impact loads calculated from the simulation. The rotor mast shall not fail and the transmission shall not be displaced into occupiable space when the main rotor composite blade impact into a 8 inch rigid cylinder in diameter on the outer 10% of the blade at operational rotor speed. To calculate the reaction loads at the spherical bearing and lead-lag damper, blade impact analysis was performed with FE model consist of composite blade, tree(or rigid cylinder) using elastic-plastic with damage material and several contact surfaces which were created to describe a progress of actual failure. Also, the reaction loads were investigated in change of blade rotation speed and pitch angle.

• Journal of the Korean Society for Aeronautical & Space Sciences
• /
• v.37 no.3
• /
• pp.301-306
• /
• 2009

In this study a 3-component rotating balance, which is designed to measure the thrust (Fz) and two moment components (Mx, My) simultaneously for a rotor test jig, is designed and its performance is validated experimentally. The low voltage signal from the strain gages mounted on the balance is amplified with a rotating amplifier, which is then fed through a slip-ring unit into the data acquisition system. In order to validate the accuracy of the calibration matrix obtained from a static calibration test, an additional reaction type balance is used to measure the thrust from a model rotor simultaneously, and shows very good result. Finally, the expanded uncertainty value, which is obtained from ISO method is estimated to be $2.82\times10^{-1}$, and the balance turns out to be reliable.

• Journal of the Korean Society for Aeronautical & Space Sciences
• /
• v.46 no.9
• /
• pp.782-789
• /
• 2018

Multi-Function Display (MFD) of Korean Utility Helicopter (KUH) displays image information(navigation, flight, topographical and maintenance information) delivered from Mission Computer (MC) during flight operation. The abnormal display of MFD such as flickering phenomenon was identified in the system development. It was solved by improving the shielding performance of the DVI cable and changing the DVI cable installation path at the first mass production. However, it was occurred again when the aircraft was operated for one or two years after delivery. It was also identified in the evaluation process of the derivative helicopters. Therefore, a comprehensive review of the aircraft system level has been performed to solve the problem of MFD malfunction at first and then a design improvement plan was derived by improving the DVI cable. In this paper, the causes of MFD anomalies are analyzed and also the process of design improvement are summarized. The validity of the improvement has been verified through the DVI cable assembly comparison test, SIL/ground/flight test.

• Journal of Intelligence and Information Systems
• /
• v.14 no.1
• /
• pp.85-100
• /
• 2008

The digital economy era is a knowledge-based society. Many organizations have been establishing KMS (Knowledge Management System), and there are no exceptions in military ones. In this study, we analyze the influencing factors for KMS utilization in a military organization, which is a specialized one. For this purpose, we investigate the current status of KMS of ROKAF (Republic Of Korea Air Force), derive problems and issues, and try to find out solutions for the KMS utilization in military organizations by analyzing a survey. At first, we derive three characteristics of the military organization that affect the knowledge sharing : formalization of organization, trust of organizational culture, and top management's will. And we verified that the users, who recognize that the top management has the will for the knowledge sharing, have high recognition for the knowledge sharing and utilize KMS more than others. This study shows that it is very important for the top management to participate in the knowledge sharing voluntarily especially in the military organization.

• Proceedings of the KSRS Conference
• /
• 2003.11a
• /
• pp.654-655
• /
• 2003

Korea has experienced 10 a Cochlodinium polykrikoides red tide outbreaks during the last 10 years (1993-2002). The monitoring activities at National Fisheries Research and Development Institute (NFRDI) in Korea have been extended to all the coastal waters after the worst of fish killing by C. polykrikoides blooms in 1995. NFRDI is looking forward to finding out the feasibility of red tide detection around Korean waters using satellite remote sensing of NOAA/AVHRR, Orbview-2/SeaWiFS, IRS-P4/OCM and Terra/MODIS on real time base. In this study, we used several alternative methods including climatological analysis, spectral and optical methods which may offer a potential detection of the major species of red tide in Korean waters. The relationship between the distribution of SST and C. polykrikoides bloom areas was studied. In climatological analysis, NOAA, SeaWiFS, OCM satellite data in 20th and 26th August 2001 were chosen using the known C. polykrikoides red tide bloom area mapped by helicopter reconnaissance and ground observation. The 26th August, 2001 SeaWiFS chlorophyll a anomaly imageries against the imageries of non-occurring red tide for August 20, 2001 showed the areas C. polykrikoides occurred. The anomalies of chlorophyll a concentration from satellite data between before and after red tide outbreaks showed the similar distribution of C. polykrikoides red tide in 26th August, 2001. The distribution of the difference in SST between daytime and nighttime also showed the possibility of red tide detection. We used corrected vegetation index (CVI) to detect floating vegetation and submerged vegetation containing algal blooms. The simple result of optical absorption from C. polykrikoides showed that if we use the optical characteristics of each red tide we will be able to get the feasibility of the red tide detection.

• Journal of the Korean Society of Industry Convergence
• /
• v.22 no.6
• /
• pp.665-671
• /
• 2019

The estimated on-site accident rate in Forestry is relatively high. According to statistics of the accident, in the recent 5 years, from 2014 to 2018, forestry accidents have resulted in 98% of injuries and 87% of fatalities. Especially, there are significant geographical constraints to access to the scene in case of an accident. Even though the capacity of first aid capacity is notably emphasized its importance to minimize the scale of damages, the relevant employees have been educated only basic first aid, which is not considered circumstances or geographic limitations, by Occupation Safety and Health Acts. Therefore, the purpose of this study is to derive a direction for a forest emergency service system to increase forestry workers' survival and prevent secondary injury through securing 'Golden Time.' This study conducts analyzing relevant laws and regulations in domestic and international settings as well as looking at several concerned accident cases. The outcome of analysis presents an issue regarding the implementation of onsite first aid in forestry and existing risk factors depending on the working process. Finally, we suggest two ways to improve the forest emergency service that are 1) an appropriate curriculum and kit for forest first aid; and 2) a system for emergency transfer through sharing information between National Fire Agency (NFA) and emergency medical service center, and emergency and rescue mission using helicopter from NFA and Korea Forest Service.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
• /
• v.25 no.4
• /
• pp.279-287
• /
• 2007

The increased availability of portable, low-cost, high resolution video equipments have resulted in a rapid growth of the applications for video sequences. These video devices can be mounted in handhold unit, mobile unit and airborne platforms like maned or unmaned helicopter, plane, airship, etc. This paper describes the feasibility fur generating image map from the experimental results we designed to track the interested points extracted by KLT operator in the neighboring frames and implement image matching for each frames taken from UAV (Unmaned Aerial Vehicle). In the image registration for neighbourhood frames of aerial video, the results demonstrate the successful rate of matching slightly decreases as the drift between frames increases, and also that the stable photographing is more important matching condition than the pixel shift.

• Fire Science and Engineering
• /
• v.26 no.4
• /
• pp.10-17
• /
• 2012

This study classifies the fire suppression measures implemented by wooden temples into four types according to availability of the pump trucks (water tanks) at the fire sites. And this study outlines the strategies and methods based on each type of fire suppression measure. The results show that the fire suppression strategy applied in general buildings is also employed in temples where pump trucks (water tanks) and fire-fighting water are available. For temples where trucks and water are not available, the helicopter, water bag, fire suppression strategy focused on water supply link, automatic transmission system of a fire engine's level by using radio communication network, and water bladder are used. In addition, general four-wheel-drive vehicles equipped with fire fighting tools such as motor pump, hose, nozzle, and water bladder should be deployed in fire stations around the temples. A fire suppression strategy using A-type ladders is also required.

• Aerospace Engineering and Technology
• /
• v.7 no.1
• /
• pp.15-23
• /
• 2008

This paper describes the structural analysis results of KARI General Small-scaled Rotor Test System (GSRTS) operated in KARI to verify operational safety. This GSRTS was developed to conduct a froude and mach small-scaled rotor test. This analysis was performed to investigate the structural Factor of Safety for the various small-scale rotor system like articulated or hingeless rotor and to check the operational capability using given operational design load. Specially, drive system has several bearings, mechanical gears, shaft, etc. and these parts must be required to achieve an operational safety. The calculation was done by using geometric data and material properties by analytical method. This rotor test system should be operated within these calculated Factor of Safety. Furthermore, the operational limitation should be defined as applied to small-scale rotor system of KUH in future.