• Magazine of the Korean Society of Hazard Mitigation
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• v.9 no.2
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• pp.38-46
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• 2009

• Advances in aircraft and spacecraft science
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• v.4 no.6
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• pp.651-677
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• 2017

For the past ten years' efforts have been made to introduce environmentally-friendly "green" electric-taxi and maneuvering airplane systems. The stated purpose of e-taxi systems is to reduce the taxiing fuel expenses, expedite pushback procedures, reduce gate congestion, reduce ground crew involvement, and reduce noise and air pollution levels at large airports. Airplane-based autonomous traction electric motors receive power from airplane's APU(s) possibly supplemented by onboard batteries. Using additional battery energy storages ads significant inert weight. Systems utilizing nose-gear traction alone are often traction-limited posing serious dispatch problems that could disrupt airport operations. Existing APU capacities are insufficient to deliver power for tractive taxiing while also providing for power off-takes. In order to perform comparative and objective analysis of taxi tractive requirements a "standard" taxiing cycle has been proposed. An analysis of reasonably expected tractive resistances has to account for steepest taxiway and runway slopes, taxiing into strong headwind, minimum required coasting speeds, and minimum acceptable acceleration requirements due to runway incursions issues. A mathematical model of tractive resistances was developed and was tested using six different production airplanes all at the maximum taxi/ramp weights. The model estimates the tractive force, energy, average and peak power requirements. It has been estimated that required maximum net tractive force should be 10% to 15% of the taxi weight for safe and expeditious airport movements. Hence, airplanes can be dispatched to move independently if the operational tractive taxi coefficient is 0.1 or higher.

• Journal of computational fluids engineering
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• v.13 no.4
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• pp.66-71
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• 2008

This research computes the viscous flow field and aerodynamics around the model of a commercial passenger airplane, Boeing 747-400, which cruises in transonic speed. The configuration was realized through the reverse engineering based on the photo scanning measurement. In results, the pressure coefficients at the several wing section on the wing surface of the airplane was described and discussed to obtain the physical meaning. The lift coefficient increased almost linearly up to $17^{\circ}$. Here the maximum lift occurred at $18^{\circ}$ according to the angle of attack. And the minimum drag is expected at $-2^{\circ}$. The maximum lift coefficient occurred at the Mach number 0.89, and the drag coefficient rapidly increased after the Mach number of 0.92. Also shear-stress transport model predicts slightly lower aerodynamic coefficients than other models and Chen's model shows the highest aerodynamic values. The aerodynamic performance of the airplane elements was presented.

• Journal of Korean Society of Transportation
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• v.23 no.4 s.82
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• pp.7-16
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• 2005

Rejected Takeoff Accidents are not common. but if occurred, it leads to big disaster From the year of 1959, when Jet Transport service opened, to the year of 2000, Rejected Takeoff accidents/incidents occurred total of 94 cases. All cases led to overrun, and major cause is to initiate stopping maneuvers over $V_1$, takeoff decision speed, according to National Transport Safety Board of America. Similar results are represented in Aviation Safety Reporting System of National Aeronautics and Space Administration. So I believe that it is worth studying if Airplane Flight Manual, which is the reference Performance criteria, is appropriate to operations of line pilots. The definition of $V_1$ has been revised a couple of times and Rejected Takeoff Certification Standards for Transport Airplanes was changed in 1998. It shows that up to now there are some portions unreasonable. This study focused on gathering the pilot's tendency for current Rejected Takeoff Procedures of K airlines and analyze the factors they concern. I chose B777 airplane and actually measured the recognition and reaction time of the rejected takeoff transitions through Simulators. And compared the results with the data of flight test and Airplane Flight Manual.

• Journal of the Korean Society of Propulsion Engineers
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• v.22 no.4
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• pp.117-124
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• 2018

USA and Europe are leading the transport airplane industry. In Asia-Pacific region, air transportation and MRO industries are forecasted to be grown up rapidly. Furthermore, Japan and China entered into design and manufacture state of regional airplane, while developing countries entered into severe struggle competition for MRO industry. Global aircraft MRO and engine MRO industries are forecasted 3.4% and 7% annual growth respectively in the next decade. In this paper, authors propose promotion strategy for technology intensive MRO of aircraft engine to create a higher value-added business.

• Environmental Sciences Bulletin of The Korean Environmental Sciences Society
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• v.4 no.4
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• pp.263-271
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• 2000

To investigate the distribution of air pollutants dispersion in the horizontal wind fields, a chaff release experiment was carried out by an airplane. The temporal and spatial variations of a chaff plume from an elevated point source using the WSR-88D(NEXRAD) radar. The observed profiles of radar reflectivity were compared with the Gaussian diffusion model at slightly unstable atmospheric condition. The present study shows that the distributions of radar reflectivity from chaffs and their concentration by the model are in general agreement with time variation. The dispersion coefficients in downwind($\sigma$(sub)x) and crosswind($\sigma$(sub)y) spread data exceeded what has generally been found at Pasquill and Brigg\`s estimates. As a result, it was clearly shown that horizontal and vertical diffusion coefficients are more accurately determined as compared with theoretical coefficients. At longer diffusion distances(than 10km), a radar observation provided the determination of maximum range and diffusion height more qualitatively, too.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.9 no.7
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• pp.1425-1431
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• 2005

In this paper, we consider the ISR(Intelligence, Surveillance, and Reconnaissance) system which collects the imagery intelligence from an airplane and CDL(common data link) communication system which transports the information obtained by the ISR system. The IMINT(imagery intelligence) consists of MPEG-2 transport stream packets and they transmit through CDL. We have some simulations for communication performances of CDL and show performance improvements using convolutional coding. We have compared BER performances under AWGN channel and fading channel which is caused by the velocity of an airplane.

• Structural Engineering and Mechanics
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• v.78 no.5
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• pp.611-622
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• 2021

Composite material-due to low density-causes weight savings, which results in lower fuel consumption of transport vehicles. The aim of the research was to change the existing base-plate of the aluminum airplane container with the composite sandwich plate in order to reduce the weight of the containers of cargo aircrafts. The newly constructed sandwich plate consists of aluminum honeycomb core and composite face-sheets. The face-sheets consist of glass or carbon or hybrid fiber layers. The orientations of the fibers in the face-sheets were 0°, 90° and ±45°. Multi-objective optimization method was elaborated for the newly constructed sandwich plates. Based on the design aim, the importance of the objective functions (weight and cost of sandwich plates) was the same (50%). During the optimization nine design constraints were considered: stiffness, deflection, facing stress, core shear stress, skin stress, plate buckling, shear crimping, skin wrinkling, intracell buckling. The design variables were core thickness and number of layers of the face-sheets. During the optimization both the Weighted Normalized Method of the Excel Solver and the Genetic Algorithm Solver of Matlab software were applied. The mechanical properties of composite face-sheets were calculated by Laminator software according to the Classical Lamination Plate Theory and Tsai-Hill failure criteria. The main added-value of the study is that the multi-objective optimization method was elaborated for the newly constructed sandwich structures. It was confirmed that the optimal new composite sandwich construction-due to weight savings and lower fuel consumption of cargo aircrafts - is more advantageous than conventional all-aluminum container.

• Current Industrial and Technological Trends in Aerospace
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• v.8 no.2
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• pp.105-112
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• 2010

Aircraft accidents are characterized by substantial and extensive damage: the destruction of hulls and the fatalities of passengers. Health and Usage Monitoring Systems (HUMSs) are being developed as a technological approach to prevent the aircraft accident. In Korea, a project to develop HUMS for small airplane is being executed by funding of by Ministry of Land, Transport and Maritime Affairs. In this paper, global R&D trends of HUMS to prevent aircraft accident are described. An on-going Korean HUMS project is also explained, especially for system configuration, functionality and expected achievement.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2017.05a
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• pp.188-193
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• 2017

USA and Europe are leading a transport airplane industry. In Asia-Pacific region, air transportation and MRO industries are forecasted to be grown up rapidly. Furthermore, Japan and China entered into design and manufacture state of regional airplane, and developing countries entered into severe struggle competition for MRO industry. Global aircraft MRO and engine MRO industries are forecasted 3.4% and 7% growth respectively in next decade. In this paper, authors propose promotion strategy for technology intensive MRO of aircraft engine to create a higher value-added business.