• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.42 no.5
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• pp.406-414
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• 2014

In this paper, it is introduced characteristics of FMCW-type Radar Altimeter for KUH, and its defects occurred during ground/flight test in initial product phase. In addition, it is also described 'data/control flow model' based fault analysis results of S/W and processes of verifying improvement design through flight test as well as aircraft system integration test called MEP SIL. As a result of design improvement and verification, it is validated that settling the defects and improving not only safety but also capability of the KUH.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.34 no.10
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• pp.80-91
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• 2006

A method of multidisciplinary education has been implemented for satellite design, based on HAUSAT-1 and 2 ultra-small satellite development projects, in order to provide practical knowledge and experience to students studying satellite engineering. HAUSAT-1 was the nation's first 1kg-class ultra-small satellite. HAUSAT-2 nano-satellite is currently under a Proto-Flight Model development. These design projects make it possible to achieve the goal of science and technical research, which is representative of a university function, and the goal of molding professionals through providing an integrated function of system design education. An integrated system design, like satellite system, provides all participating students with an opportunity to directly/indirectly experience the entire system development process and encourage growth of multidisciplinary system education that has lately become an important issue.

• Journal of the Korean Association of Geographic Information Studies
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• v.8 no.1
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• pp.49-62
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• 2005

The VR (virtual reality) simulator such as helicopter simulation needs virtual environment of existing urban area. But the real urban environment keeps changing. We need a modeling method to make use of the GIS data that are updated periodically. The flight simulation needs to visualize not only buildings in near distance but also a large number of buildings in the far distance. We propose a method for modeling urban environment from aerial image and digital map with a comparatively small manual work. Image based modeling is applied to urban model which considers the characteristic of Korean cities. Buildings in the distance can be presented without creating a lot of polygons. Proposed method consists of the pre-processing stage which prepares the model from the GIS data and the modeling stage which makes the virtual urban environment. The virtual urban environment can be modeled with the simple process which utilizes the height map of buildings.

• Journal of IKEEE
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• v.23 no.4
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• pp.1423-1429
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• 2019

Recently, a system that supports efficient interaction, a human machine interface (HMI), has become a hot topic. In this paper, we propose a new real time low-cost hand gesture control system as one of vehicle interaction methods. In order to reduce computation time, depth information was acquired using a time-of-flight (TOF) camera because it requires a large amount of computation when detecting hand regions using an RGB camera. In addition, fourier descriptor were used to reduce the learning model. Since the Fourier descriptor uses only a small number of points in the whole image, it is possible to miniaturize the learning model. In order to evaluate the performance of the proposed technique, we compared the speeds of desktop and raspberry pi2. Experimental results show that performance difference between small embedded and desktop is not significant. In the gesture recognition experiment, the recognition rate of 95.16% is confirmed.

• The Bulletin of The Korean Astronomical Society
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• v.43 no.1
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• pp.51.3-52
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• 2018

Since Voyager 1 passed the Heliopause in 2012, it has provided the observations of the charged particles in the local interstellar medium. However, Voyager 1 only provides the information along with its trajectory. In order to understand the global view of the interstellar plasma flow surrounding the Heliopause, we need another tool. When the interstellar plasmas approach the Heliopause, the ions are deflected around the Heliopause due to the draping of the interstellar magnetic field. The draping of the interstellar magnetic field is strongly connected with the shape of the Heliopause. A fraction of the diverted ions exchanges their charges with the undisturbed primary interstellar neutral atoms, and then the ions become neutral atoms called the secondary interstellar neutral atoms. The newly created neutral atoms carry information on the diverted flow of the interstellar ions, and a fraction of them can travel to the Sun. Therefore, the secondary component of the interstellar neutrals is an excellent diagnostic tool to provide important information to constrain the shape of the Heliopause. The secondary interstellar neutrals are observed by Interstellar Boundary Explorer (IBEX) at Earth's orbit. Since 2009, two energetic neutral atom cameras on IBEX have measured neutral atoms and it has provided sky maps of neutral atoms. In this presentation, we will discuss the directional distribution of the secondary interstellar neutrals at Earth's orbit. In the sky maps, the primary interstellar neutral gas is seen between $200^{\circ}$ and $260^{\circ}$ in ecliptic longitude and the secondary components are seen in the longitude range of $160^{\circ}-200^{\circ}$. We also present a simplified model of the outer heliosheath to help interpret the observations of interstellar neutrals by the IBEX-Lo instruments. We extract information on the large-scale shape of the Heliopause by comparing the neutral flux measured at IBEX along four different look directions with simple models of deflected plasma flow around hypothetical obstacles of different aspect ratios to the flow. Our comparisons between the model results and the observations indicate that the Heliopause is very blunt in the vicinity of the Heliospheric nose, especially compared to a Rankine half-body or cometary shape.

• Tunnel and Underground Space
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• v.25 no.6
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• pp.527-533
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• 2015

This study performed an on-site demonstration of the topographic surveying technique at a large-scale open-pit limestone mine in Korea using a fixed-wing unmanned aerial vehicle (UAV, Drone, SenseFly eBee). 288 sheets of aerial photos were taken by an automatic flight for 30 minutes under conditions of 300 m altitude and 12 m/s speed. Except for 37 aerial photos in which no keypoint was detected, 251 aerial photos were utilized for data processing including correction and matching, then an orthomosaic image and digital surface model with 7 cm grid spacing could be generated. A comparison of the X, Y, Z-coordinates of 4 ground control points measured by differential global positioning system and those determined by fixed-wing UAV photogrammetry revealed that the root mean squared errors were around 15 cm. Because the fixed-wing UAV has relatively longer flight time and larger coverage area than rotary-wing UAVs, it can be effectively utilized in large-scale open-pit mines as a topographic surveying tool.

• Journal of Physiology & Pathology in Korean Medicine
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• v.22 no.5
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• pp.1215-1222
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• 2008

Recent studies indicate that the deposition of ${\beta}$-amyloid ($A{\beta}$) is associated with the pathogenesis of Alzheimer's disease (AD), but the underlying mechanism is not clear yet. To investigate the effects of Jangwonhwangagambang (JWHG) extract on AD pathogenicity, we have generated transgenic Drosophila model in which GMR-APP-GAL4/UAS-GRIM system was designed to overexpress amyloid precursor protein(APP), We examined fly's survival ratio, flight behavior, and morphological patterns of chest and eye. We found that JWHG treatment improved fly's survival ratio by inhibiting apoptosis and flight behavior. APP-GRIM transgenic flies treated with JWHG showed had significantly lower levels of APP deposition in the chest and eye compared to control animals. JWHG treatment further inhibited chest and eye degeneration. These results suggest that JWHG prevents APP-induced neurotoxicity, and thus may be applicable for the development of preventive or therapeutic agents for AD treatment.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.26 no.3
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• pp.311-320
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• 2008

A LIDAR can rapidly generate 3D points by densely sampling the surfaces of targets using laser pulses, which has been efficiently utilized to reconstruct 3D models of the targets automatically. Due to this advantage, LIDARs are increasingly applied to the fields of Defense and Security, for examples, being employed to intelligently guided missiles and manned/unmanned reconnaissance planes. For the prior verification of the LIDAR applicability, this study aims at generating simulated LIDAR data. Here, we derived the sensor equation by modelling the geometric relationships between the LIDAR sub-modules, such as GPS, IMU, LS and the systematic errors associated with them. Based on this equation, we developed a program to generate simulated data with the system parameters, the systematic errors, the flight trajectories and attitudes, and the reference terrain model given. This program had been applied to generating simulated LIDAR data for urban areas. By analyzing these simulated data, we verified the accuracy and usefulness of the simulation. The simulator developed in this study will provide economically various test data required for the development of application algorithms and contribute to the optimal establishment of the flight and system parameters.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.40 no.5
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• pp.395-404
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• 2012

This paper presents computations of the dynamic derivatives of three dimensional flight vehicle configurations using CFD. The pitch dynamic derivatives are computed from the pitch sinusoidal motion, while the roll damping is computed based on steady state calculation using a non-inertial frame method. The Basic Finner and the SDM(Standard Dynamic Model) are chosen for the benchmark tests against other numerical and experimental results. For the flow calculations, a 3-D Euler solver that can be run both on the non-inertial frame and on the inertial frame is developed. A dual-time stepping method is applied for the unsteady time accurate simulations. A good agreement of pitch-roll dynamic derivatives with previously published numerical results and the experimental results is observed.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.40 no.5
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• pp.461-466
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• 2012

This paper describes the development and test result of X-band Transmitter flight model(FM) of STSAT-3 by satellite research center(SaTReC), KAIST. The communication sub-system of STSAT-3 is consist of two different frequency band channels. S-band frequency is used for Telemetry & Command, and X-band frequency is used for mission data. Payload observations data in Mass Memory Unit (MMU) is modulated by QPSK modulator in X-band Transmitter, and then QPSK modulation signal is transmitted to antenna through transfer switch. In this Paper, we described the results of modulation, low-pass filter design, power amp development, and switch test. The FM XTU is delivered Spacecraft Assembly, Integration and Test(AIT) level through the completion of functional Test and environmental(vibration, thermal vacuum) Test successfully.