• Tribology and Lubricants
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• 제17권4호
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• pp.312-320
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• 2001

In magnetic hard disk drives, higher areal recording density requires reduction of head-disk spacing. To overcome the increase of stiction associated with reduction of head-disk spacing, a padder slider, which adds pads to slider's air bearing surface, can be one of the practical solution for sub 20 nm flying height, and even for near contact recording. This study investigated the tribological characteristics of a padder slider. A padder slider took off slowly but showed less friction force than a normal slider. The hot/dry CSS test and drag test indicated that pad wear of a padder slider was negligible. The tribological performance of disk is an important factor to be considered. In particular, less carbon overcoat layer of the disk will result in higher stiction and wear in slider/disk interface. In conclusion, a padder slider shows encouraging tribological performances for practical use in HDD.

• 정보저장시스템학회논문집
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• 제2권1호
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• pp.71-78
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• 2006

In this work, we propose a new type of HDD Load/Unload(L/UL) suspension featuring shape memory alloy(SMA). The mechanical and thermal properties of the SMA film with respect to the material phase states are experimentally estimated and the SMA film is carefully integrated to the suspension. In order to obtain the desirable dynamic characteristics of the suspension during L/UL process, the design parameters of the SMA film such as geometric properties are determined by considering the vibration modes of the suspension related to the L/UL performance. After analyzing the modal characteristics of the proposed suspension, L/UL performance is evaluated through L/UL simulation by observing the vibration motion and minimum flying height of the slider during L/UL process.

• 한국컴퓨터정보학회논문지
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• 제24권1호
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• pp.115-120
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• 2019

In this paper, we propose a system and an intuitive interface that can create an athletic scene among athletes. We allow you to enter motion as if you were playing a game, so that the user's action becomes the player's action. The user can take various actions in front of the motion sensor and control the object flying to him. When a user specifies an opponent to pass or attack, and takes appropriate action in front of the motion sensor, the movement trajectory of the object is automatically generated by the physical optimization technique in accordance with the motion. In this way, you can create scenes where multiple players play together in a virtual environment. The method of this paper will be very useful for rapid prototyping for cinematic trailers of based on athletics games or animations.

• 한국멀티미디어학회논문지
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• 제18권9호
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• pp.1047-1057
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• 2015

In this paper, we propose an effective wireless transmission technology, under poor wireless transmission channel surroundings caused by speedy flying, that are able to transmit high quality video recording information and surveillance data via accessing to various wireless networking services architecture such as One-on-One, Many-on-One, One-on-Many, Over the Horizon. The Real-Time Position Analysis(RAPA) method is also suggested to provide more meaningful video information of shooting area. The suggested wireless transmission technology and RAPA can make remote control of UAV's flight route to get valuable topography information. Because of the benefit to get both of video information and GPS data of shooting area simultaneously, the result of study can be applied to various application sphere including UAV that requires high speed wireless transmission.

• 한국측량학회지
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• 제40권4호
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• pp.351-357
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• 2022

In this study, a direction for deregulation that can increase the use of drones in the field of spatial information is presented. Regulations and administrative procedures for drone operation showed similar procedures in Japan, the United States, and Korea, such as reporting flight equipment, driver's license, and prohibition of flying within a specific flight zone. In the United States, policies to encourage the use of commercial drones have been implemented, and Japan has slightly tightened regulations on drone operation to protect the Olympics and important national facilities. As a result of the study, in the area where drone operation is restricted for geospatial data construction, Korea was setting the largest area, and GIS analysis showed that Korea's drone flight restricted area was more than 19.4% of the country's land area. In order to increase the utilization of drones in the construction and utilization of spatial information in the future, it is necessary to reset the drone flight restriction zone and reduce the area of the drone flight restriction zone. In addition, it was found that Korea is the only country that has formal and specific regulations on geospatial information security management. In order to increase the construction of geospatial information using drones, it is necessary to ease GSD (Ground Sample Distance)regulations.

• 한국측량학회지
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• 제26권6호
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• pp.599-609
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• 2008

전자 및 디스플레이 기술의 진보에 따라 공간정보 분야는 급속히 발전되고 있으며, 다양한 공간정보 콘텐츠의 3차원 입체화가 기술이 상용화되고 있다. 공간정보기술은 여러 분야에서 의사결정에 중요한 역할을 하고 있지만, 3차원 데이터 및 결과물은 2차원 평면상에서 시각화되고 있다. 그러나 실세계 공간에 존재하는 지형지물 등 다양한 3차원 객체들을 2차원 평면에서 시각화한 결과를 기반으로 의사결정에 활용하는 것은 한계가 있다. 그러므로 본 연구에서는 3차원의 객체를 실감적이고 입체적으로 디스플레이 하기 위하여 가상의 3차원 공간 좌표계를 형성하였다. 입체 디스플레이를 위한 공간좌표계상에서 관측자의 위치, 방향, 영상의 크기 및 중복도, 축척 등을 동적으로 설정할 수 있도록 공선조건식을 적용하여 관측자의 동적인 시점을 고려하여 신속하게 입체영상을 생성하고 디스플레이 할 수 있는 방법을 개발하였다. 생성된 3차원 대상물의 회전, 이동 및 축척변화에 대응되는 다양한 관측자 시점에서 실시간 입체영상을 생성하였으며, 또한 flying-trough 및 walking-trough를 시뮬레이션할 수 있는 입체 동영상 제작 알고리즘을 구현하였다. 3차원 대상물을 입체로 디스플레이하기 위해서는 양안시차의 원리에 의해 대상물을 좌안 및 좌측영상으로 분리하고 무안경식, 편광식, 여색방식 등의 입체시 기법을 적용하여 동시에 디스플레이하여야 한다. 본 연구는 입체 모니터상에서 실감적 입체 디스플레이 기법을 구현하여 실세계에 존재하는 3차원 대상물을 효율적이고 실감적으로 생성하므로써 지형공간 데이터의 입체 시각화를 향상시킬 수 있다. 특히 차세대 모니터인 무안경식 입체 모니터에 디스플레이 할 수 있는 지형공간 데이터의 입체 콘텐츠 제작 방법을 개발하여 무안경식 모니터의 GIS 분야에서의 활용 가능성을 연구하는데 목적이 있다.

• 제어로봇시스템학회논문지
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• 제19권2호
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• pp.158-163
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• 2013

The fusion of the GPS (Global Positioning System) and DR (Dead Reckoning) is widely used for position and latitude estimation of vehicles such as a mobile robot, aerial vehicle and marine vehicle. Among the many types of aerial vehicles, grater focus is given on the quad-rotor and accuracy of the position information is becoming more important. In order to exactly estimate the position information, we propose the fusion method of GPS and Gyroscope sensor using the DEKF (Dual Extended Kalman Filter). The DEKF has an advantage of simultaneously estimating state value and a parameter of dynamical system. It can also be used even if state value is not available. In order to analyze the performance of DEKF, the computer simulation for estimating the position, the velocity and the angle in a circle trajectory of quad-rotor was done. As it can be seen from the simulation results using own proposed DEKF instead of EKF on own fusion method in the navigation of a quad-rotor gave better performance values.

• 한국방송∙미디어공학회:학술대회논문집
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• 한국방송공학회 2009년도 IWAIT
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• pp.742-745
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• 2009

This paper proposes a wireless LAN antenna system that tracks an object automatically by using image-based tracking. The proposed system consists of a camera and a pan-tilt unit in addition to a directional wireless LAN antenna. The camera and the directional antenna are set in same direction and they are set on the pan-tilt unit. A target object which has a wireless LAN receiver is tracked by using images captured by the camera. And the directional antenna faces in same direction as the camera by the pan-tilt unit. Therefore, the directional antenna keeps pointing the receiver, and a transmitting efficiency is improved. A result of a fundamental experiment shows that a receiver attached to a flying airship was tracked by a prototype of the proposed antenna system. The airship flied about, and the proposed antenna system was set on a roof of a building. The experimental result indicates an effectiveness of the proposed system compared to the conventional directional LAN antenna.

• 한국국방경영분석학회지
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• 제2권1호
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• pp.127-143
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• 1976

The purpose of this thesis is to study the optimal arrangement of aircraft instrument panels through the human factors approach. Human factors engineering is the process of effectively fitting the human component to the machine component in any man-machine system. The human factors. are especially important to an aircraft pilot who must constantly shift his attention between the instrument panel within the cockpit and the surrounding area of the aircraft. The preliminary part of this study is to find the general patterns of the Korean pilot's eye movements during their various flying maneuvers, and which instruments require the most attention while in flight. It is assumed that all pilots have a general pattern of eye movement when observing the aircraft instrument panel and that an optimum arrangement would be to minimize the eye travel distance between instruments. In this thesis the arrangements of instruments is taken to be the independent variable and the eye travel distance between instruments the dependent variable. la order to compile the information necessary for this study, sixty Korean Air Force pilots were interviewed and requested to complete information forms. These information forms listed various flying maneuvers and listed each instrument used on the instrument panel. The compilation of the information on these completed forms listed the instruments most frequently used by the pilots. The second part of this study was to determine the optimum instrument arrangement. It was necessary to study the various number of possible arrangements of instruments depending upon the number of instruments involved. Therefore, these instruments are grouped by two major functions, The flight instruments were subdivided into three groups, and the engineering instruments were subdivided into six groups. With this subdivision we arrive at the possible number of arrangements of 4,320. Through the simulation method, total eye travel distance for each of these 4,320 arrangements is calculated and the arrangement which appears to be of optimum distance between the most frequently used aircraft instruments is determined. The results of this study indicate that the optimum distance between instruments would be 33,028cm and that the corresponding distance of the instrument panel now being used is 34,288cm. Therefore, an increased efficiency of $3.8\%$ would be realized if the existing aircraft instrument panel were re-arranged according to layout proposed in this thesis.

• 제어로봇시스템학회논문지
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• 제21권1호
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• pp.21-27
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• 2015

A conventional fire detection has been developed based on images captured from a fixed camera. However, It is difficult to apply current algorithms to a flying Quad-rotor to detect fire. To solve this problem, we propose that the fire detection algorithm can be modified for Quad-rotor using Ego-motion compensation. The proposed fire detection algorithm consists of color detection, motion detection, and fire determination using a randomness test. Color detection and randomness test are adapted similarly from an existing algorithm. However, Ego-motion compensation is adapted on motion detection for compensating the degree of Quad-rotor's motion using Planar Projective Transformation based on Optical Flow, RANSAC Algorithm, and Homography. By adapting Ego-motion compensation on the motion detection step, it has been proven that the proposed algorithm has been able to detect fires 83% of the time in hovering mode.