• Journal of the Korean Society for Aviation and Aeronautics
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• v.7 no.1
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• pp.41-55
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• 1999

In case of KOREA, many difficulties are expected for pilots to adapt to the flight operational environment changes which we will meet suddenly in anytime of the future as the operating plan for GPS is not fully prepared yet. It is because GPS operation is rather difficult compared to other navigation equipments, and it takes much time and experience to be familiar with GPS instrument approach procedure. First of all, it is keenly required to establish GPS instrument approach procedure for the local airports to be familiar with GPS instrument approach procedure. We would like to introduce GPS instrument approach procedure for the Cheju International Airport as a basic model to help you to understand it.

• Journal of the Korean Society for Aviation and Aeronautics
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• v.14 no.2
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• pp.39-44
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• 2006

The unsteady vortex lattice method is used to model lead-lag in flapping motions of a rectangular flat plate wing. The results for plunging and pitching motions were compared with the limited experimental results available and other numerical methods. They show that the method is capable of simulating many of the features of complex flapping flight. The lift, thrust and propulsive efficiency of a rectangular flat plate wing have been calculated for various lead-lag motion and reduced frequency with an amplitude of flapping angle(20o). To describe a motion profile of wing tip such as elliptic, line and circle, the phase difference of flapping and lead-lag motion was changed. And the effects of the motion profile on the aerodynamic characteristics of the flapping wing are discussed by examination of their trends.

• Smart Structures and Systems
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• v.2 no.3
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• pp.237-251
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• 2006

Piezoelectric sensors have many applications in geotechnical engineering, especially in characterizing soils through measurement of wave velocities. Since mechanical properties of a material are closely associated with wave velocities, piezoelectric sensors provide a reliable and non-destructive method for the determination of soil properties. This paper presents results of recent research on measuring stiffness of a wide range of soils such as clay, sand, and gravel, characterizing anisotropic properties of soil induced by external loading, measuring stiffness of base and subgrade materials in the pavement, determining soil properties in a centrifuge model during the flight of a centrifuge, and understanding wave propagation in granular materials under micro-gravity environment using this technique.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 2004.10a
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• pp.99-115
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• 2004

From the growth of Internet technology, many e-commerce principles have been introduced in airline industry. The computer reservation systems(CRS) is the first real-time business application and considered as the earliest examples of e-commerce. In airlines, the early e-business activity was to build the web site for providing flight information to customers. Recently, many airlines are expanding the capability of the web site for selling tickets on the web to make use of the cheaper distribution channel. In this paper, we focus on the impacts of airline e-business being implemented in airline distribution channels. Using the conjoint analysis, we suggest a model for estimating the change of market sales for each distribution channel. With the empirical survey, we can find some implications on the e-business strategy and the effective internet marketing tools for airlines.

• Korean Management Science Review
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• v.33 no.1
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• pp.89-99
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• 2016

A scheduled airlift is the most critical part of the air transportation operations in ROK Air Force. The military cargo-plane routing problem is a PDPLS (pickup and delivery problem in which load splits and node revisits are allowed). The cargo which is transported by a military cargo-plane is measured in pallet. The efficiency of pallet needs to be considered with respect to its volume and weight. There are some guidelines about orders of priorities and regulations in the military air transportation. However, there are no methodologies which can raise the efficiency of flight scheduling using Operations Research (OR) theories. This research proposes the effective computing methodology and the related heuristic algorithms that can maximize the effectiveness of the path routing model.

• Bulletin of the Korean Space Science Society
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• 2004.10b
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• pp.332-336
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• 2004

This paper describes the remote tracking algorithm using measurements (azimuth, elevation, and slant range) of the radar ground station. Kalman filter model for noise reduction of the measured information is first derived by linearizing with respect to angle, angular rate, range, and range rate. And then a tracking algorithm is introduced to calculate the position of the vehicle during in-flight. The simulation results show that the algorithm is practical and effective enough tracking position of the vehicle in considerably less error.

• Journal of the Korea Institute of Military Science and Technology
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• v.3 no.2
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• pp.61-70
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• 2000

An Adaptive Positive Position Feedback method is presented for controlling the roll of the supersonic smart projectile. The proposed strategy combines the attractive attributes of Positive Position Feedback(PPF) of Goh and Caughey, and Lyapunov stability theorem. The parameters of Adaptive-PFF controller are adjusted in an adaptive mauler in order to follow the performance of an optimal reference model. In this way, optimal damping and zero steady-state errors can be achieved even in the presence of uncertain or changing plant parameters. The performance obtained with the Adaptive-PPF algorithm is compared with conventional PPF control algorithm. The results obtained emphasize the potential of Adaptive-PPF algorithm as an efficient means for controlling plants such as supersonic flight systems with uncertainties in real time.

• 한국정보디스플레이학회:학술대회논문집
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• 2009.10a
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• pp.1055-1055
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• 2009

The mobility of charge carriers has been investigated in the pristine and phosphorescent materials doped host materials using time-of-flight photoconductivity technique. The field and temperature dependences of the mobility were analyzed with the Gaussian disorder model. Based on these results, we optimized white organic light emitting diodes (WOLEDs) consisting of multi-emitting layers doped with phosphorescent and fluorescent dopants. Especially, we studied the effect of each emitter position and an interlayer on the device characteristics of WOLEDs.

• Journal of the Korean Society for Aviation and Aeronautics
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• v.23 no.1
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• pp.67-73
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• 2015

The previous limited authority system capable of implementing attitude command response type and translational command response type by operating SAS actuator has the problem of early saturation of SAS actuator since SAS actuator should compensate the mechanical linkage displacement caused by control sick movement. In this paper, a limited authority system where flight control computer receives the command from the control stick which is not connected to the mechanical linkage is described. In this system the compensation by the SAS actuator is not necessary and SAS actuator saturate later. SAS actuator saturation problem can be further relaxed by using the trim actuator. This new limited authority system is applied to BO-105 model, simulation is performed for the doublet input and pirouette maneuver is also simulated and analyzed.

• Journal of Information Technology Services
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• v.10 no.1
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• pp.167-176
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• 2011

Punctuality is one of the key performance indicators of the airline industry and an important service differentiator especially for valuable customers. In addition, improvement on time performance can help achieve cost saving, i.e. the cost of airline report, which could range from 0.6% to 2.9% of their operating revenues. Therefore efficient management of punctuality is crucial for the industry. This study overcomes the limitations of existing analyses on punctuality and develops a multi-dimensional model for airport punctuality analysis. In addition to analysis of airport punctuality, visual analysis is also proposed in the study. Data was collected from actual flight data of Incheon International Airport. Using the new visual analysis method, the study discovered the pattern of the punctuality that has never studied before.