• Journal of the Korean housing association
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• v.25 no.6
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• pp.57-66
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• 2014

With regard to the pavilion buildings of Imcheonggak Gunjajeong and Donglakdang Gyejeong that are located within residential areas, this study focused on the construction background, the building owner's circumstances and the location environment of these buildings, and attempted to derive the architectural characteristics presented by these two pavilion buildings and, through this, to grasp the architect's intention of plan. The results of this study are as follows. With regard to Gunjajeong, it could be confirmed that, first, it is located in a propitious site and took the composition that follows the family ritual standards for the family rituals of the scholar-gentry class and opens to visitor access, and second, the floor height of the site and interior space was designed so that Munpilbong on the south and the Sarangchae on the west, and the Sadang on the east can be connected visually, and third, the authority and dignity of the head family were built through the symmetric 丁-shaped plane figure, the wide partition module, the form-centered building, and the hierarchical composition of the roof. On the other hand, with regard to Gyejeong, it could be confirmed that, first, it is located along the stream of Jagye valley that has no mountains in the front and in the back and took the composition that put the name symbolizing Taoist thoughts on the surrounding natural environment and was closed to visitor access but opens to nature, and second, with Jagye and Jagye surroundings as the main landscape, it built the concept of intended landscape that symbolizes the Taoist thoughts by giving names not only simply to the visible objects but also to surrounding rocks, and third, the asymmetric ㄱ-shaped plane composed a yard-centered space rather than emphasizing the shape, and connected the part of the plane with Jagye so as to be embodied as a personal inner self-perfecting place that closely communicates only with nature away from the mundane world.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.41 no.6
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• pp.473-480
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• 2013

Researches for various lunar landing technologies are in progress for the lunar exploration program planned for early 2020s in Korea. This paper shows the integrated simulation for safe lunar landing guidance/control system in powered descent phase. Generally, the lunar lander uses on/off(bang-bang) controller to control the RCS jet thrusters instead of proportional controller. In this paper, the on/off controller using phase-plane switching function, and thruster selection algorithm to control sixteen thrusters are applied. Also additional guidance commands are calculated by a proposed fuzzy logic guidance algorithm. The simulation results show that lunar lander can follow a reference trajectory which is generated by optimization method, then land on the surface safely.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.46 no.2
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• pp.133-140
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• 2018

In this paper, we develop an automated software for in-plane structural analysis of composite laminated structures. The developed software supports various failure criteria and reports the analysis results considering user's convenience. It also provides batch job analysis function based on parallel processing technique. To verify the performance of the software, we compared margin of safety(MS) calculated in the software to those obtained from in-house method and the specimen experiment. As a result of comparisons, there was an error of less than 0.01 in the in-house method and it is within about ${\pm}10%$ with the specimen experiment. In addition, we confirmed the improvement of execution speed of batch job analysis based on parallel processing technique.

• Proceedings of the Korean Institute of Interior Design Conference
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• 2004.05a
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• pp.123-126
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• 2004

This study aims to identify the change of bathroom design characteristics through the investigation of bathroom space in apartment model houses. The bathroom space of each private exclusive area was analyzed from the plane characteristics perspective such as quantity, location, size and shape. For this study, site survey and observation was performed to analyze the characteristics of plane and design based on twenty seven model houses of seven large-sized construction firms with Seoul area focused on. Research object was restricted to from ten Pyeong's apartment to sixty Pyeong's in order to understand various characteristics of twenty seven model houses. Since analysis variables were not diverse, the main three factors - frequency, percentage and an average - were represented in Microsoft Excel worksheet, focusing on the quantity of each case, design characteristics and pattern. 1) The quantity of bathrooms: It was turned out that the quantity of bathroom was one in ten Pyeong's apartment while it was two in thirty, forty, and fifty Pyeong's apartment. There were mostly two bathrooms available in twenty Pyeong's apartment even if only one was planned in few cases. All powder rooms and dress rooms in twenty and fifty Pyeong's apartment were designed to be separated and be accessible through bedroom. 2) The size of bathrooms: As private exclusive area increased, the size of bathroom for both family and couple increased. Couple bathrooms had the tendency to be equipped with shower booth and bathtub at the same place or have more tubs than family bathrooms because couple bathrooms were bigger than family bathrooms. 3) The location of bathrooms: Couple bathrooms were usually located beyond dress rooms or powder rooms while family bathrooms were mostly located at the entrance side. 4) The shape of bathrooms: Shower booth was assumed to be in general vogue because family bathrooms, for the most part, were comprised of a flush toilet, a washstand and a shower booth. In the case of couple bathrooms, a flush toilet, a washstand, a shower booth and a tub were generally equipped in more than twenty Pyeong's apartments while a tub was not installed in twenty Pyeong's apartments.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.42 no.3
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• pp.199-212
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• 2014

This paper describes an autonomous air combat guidance law using a Virtual Pursuit Point (VPP) in one-on-one close engagement for Unmanned Combat Aerial Vehicle (UCAV). The VPPs that consist of virtual lag and lead points are introduced to carry out tactical combat maneuvers. The VPPs are generated based on fighter's aerodynamic performance and Basic Fighter Maneuver (BFM)'s turn circle, total energy and weapon characteristics. The UCAV determines a single VPP and executes pursuit maneuvers based on a smoothing function which evaluates probabilities of the pursuit types for switching maneuvers with given combat states. The proposed law is demonstrated by high-fidelity real-time combat simulation using commercial fighter model and X-Plane simulator.

• Journal of the Korean Institute of Landscape Architecture
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• v.27 no.3
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• pp.58-68
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• 1999

Purpose of this thesis is to find out the relationship among the amount of change and the visual cognition, and the visual preference which people like and can feel. Through the investigation of relationships between the amount of change, which indicates the degree of visual variation and the visual preference, the amount of change and the visual cognition, and the visual preference and the visual cognition, basic design data will be supplied, which can satisfy users' desire as much as possible in the most economic way. In order to investigate the relationship between the visually produced the amount of change and preferences, graphic simulation, in which variables other than the visual change are controlled, has been proceeded. Graphic factors of the visual change in the cyber exterior space are determined on the point of location (base plane, vertical plane, overhead plane), shape, size and color. As for the relationship between the amount of change and the preference, only the size is effective. since preferences on the location, shape and color are individual preferences, no common trend can be found. Therefore, we cannot say that which shape or color is better, Since the location, shape and color are qualitative change and the size is the quantitative change, the size can be the measurable change quantity. The relationship between the amount of change of size and the degree of preference is found to be inverse U-shape, i.e., as the amount of change of size increases the degree of preference first increases and, after a certain level, decreases. The same result has been obtained in photo simulation.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.40 no.10
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• pp.857-864
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• 2016

Many plane, UAV and drone fly in the sky as development of aviation industry. Plane and UAV fly and drone's propellers rotate so fast. Impact between flying objects which have high velocity threats passengers. Also the impact damages people, building and various property. Plane's operating speed is near sound velocity(340m/s), and propeller's rotating speed is less than that. Until now, impact experiment uses gas gun to get speed and the gun needs large space to entirely air expansion. Electromagnetic launcher, especially railgun, needs smaller space than gas gun to get enough speed about 500m/s. This paper explains electromagnetic launcher's operating principle, shows making electromagnetic launcher design guide line and suggests that it is a better apparatus to get low-high velocity.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.45 no.2
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• pp.85-91
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• 2017

A wind tunnel test for 1/86 scaled down model of the NREL 5 MW offshore wind turbine was conducted to investigate the wake and flow fields. Deficit of flow speed in the wake region and variations of the turbulence intensity were measured using a hot wire anemometer at rated tip speed ratio of 11.4 m/s and a rotational speed of 1,045 rpm. According to the test results, velocity deficits along both of lateral and vertical directions were recovered within 2 rotor radii downstream from the rotating disc plane. The tip vortices effect was negligible after 5 rotor radii downstream from the rotating plane. Turbulence intensities showed maximum value around the blade tip, and decreased rapidly after one radius apart from the rotating plane, and those values were preserved until 6 rotor radii downstream.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.43 no.3
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• pp.265-271
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• 2015

In this study, optical design for small satellite camera equipped with online optical compensation movements has been conducted. Satellite camera equipped with compensation movements at M2 mirror and focal plane can guarantee the MTF performance through the focal plane image stabilization and the on-orbit optical alignment. The designed optical system is schmidt-cassegrain type that has M1 mirror of a diameter 200mm, GSD 3.8m at an altitude of 700km, and 50 % MTF performance. The performance of the designed optical system has been analyzed through the method of ray aberration curve, spot diagram, and MTF. It has been found by the optical performance analysis that the designed optical system satisfies the optical requirements of satellite camera equipped with online optical compensation movements.

• Journal of the Korean Society of Radiology
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• v.15 no.6
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• pp.813-819
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• 2021

In this study, the shielding rate of L-block-type shielding equipment used for radiation protection when radioactive fluorine is injected into the human body and the dose distribution of the space in the injection room were calculated using the Monte Carlo method. The shielding rate of the body and window parts of the L-block-type shielding equipment was 99.99%. The dose distribution calculated at a distance of 1 m was relatively high at 135°, 45°, 225°, 315°, and 180° of the XZ plane, and was calculated to be very low at 0°, 90°, and 270°. In the YZ plane, it was relatively high at 135°, 180°, and 225°, and was calculated very low at the remaining angles. The AZ and BZ planes also showed similar results to the YZ plane. In addition, it was confirmed that the shielding rate was the best in the range of 225° to 315° through the dose distribution in the horizontal direction of the source and the 45° direction above the source. These results can be used as basic data necessary for radiation protection of radiation workers.