• 반도체디스플레이기술학회지
• /
• 제4권1호
• /
• pp.35-41
• /
• 2005

An air levitation type wafer transfer system is composed of control and transfer track. Wafer transfer speed is mainly affected by air velocity of propulsion nozzle. In this study, the propulsion force coefficient was evaluated experimentally for the nozzle with 0.5mm, 0.8mm, and 1.0mm diameter. As a result, the propulsion force was largest in the smallest size of nozzle at same air velocity. The propulsion force coefficient of nozzle increases with reducing diameter of nozzle. This increment of propulsion force coefficient was enlarged remarkably at the 0.5mm diameter of nozzle.

• Journal of Electrical Engineering and Technology
• /
• 제10권3호
• /
• pp.1349-1355
• /
• 2015

It is difficult to calculate the magnetic force of an object of magnetic material in contact with other objects using the existing methods, such as Maxwell stress tensor method, magnetic charge method, or magnetizing current method. These methods are applicable for force computation only when the object is surrounded by air. The virtual air-gap concept has been proposed for calculating the contact force. However, its application is limited to magneto-static system. In this paper, we present the virtual air-gap concept for contact surface force in the eddy-current system. Its validity and usefulness are shown by comparison between numerical and experimental examples.

• 한국군사과학기술학회지
• /
• 제20권3호
• /
• pp.345-351
• /
• 2017

A wind tunnel test for the scaled parachute models was performed to verify aerodynamic characteristics for practical usage of Korean low cost low altitude aerial delivery system. The cruciform shaped cargo parachute models for heavy and light weight were ejected into wind tunnel test section; and the drag forces acting on the models in steady condition were measured in accordance with velocity. Also, the maximum opening forces during inflation were obtained and captured by a high speed camera to analyze the inflation characteristics and evaluate the design of the low cost aerial delivery system. The results showed a reliable stability and met the design requirement of delivery operation system for R.O.K Air Force.

• 드라이브 ㆍ 컨트롤
• /
• 제10권2호
• /
• pp.1-6
• /
• 2013

This study describes a method which can attenuate reaction force effectively for an air spring system composed of an air spring and auxiliary chamber. For the analysis, the nonlinear governing equation of the air spring system is derived. For a performance improvement of the system, change of the heat transfer effect and the mass flow rates is included in the analysis of the air spring system. The simulation study is presented to show the reaction force is changed by variations in heat transfer characteristics and the air spring system of isothermal process has the best performance. As a result, to improve attenuation characteristics of reaction force, a process in the air spring system should be maintained near isothermal process.

• 정보교육학회논문지
• /
• 제13권3호
• /
• pp.303-312
• /
• 2009

공군 이러닝체계 구축을 위해 공군 교육체계에 대한 선행 연구 자료 분석과 함께 공군 교육생들을 대상으로 한 설문조사를 실시하였다. 설문조사 결과 3,597명이 응답하였고, 그 결과 공군 교육생 대부분이 이러닝에 대한 경험이나 인식은 부족하나, 기회가 주어진다면 이러닝 강좌를 수강하기를 원하고 있었다. 또한, 기존의 학습 포털 시스템에 대한 기능 개선에 대한 요구가 많았고, 집합교육보다는 개별교육을, 제한된 컴퓨터실보다는 자유 공간에서 학습하기를 원하였다. 이러한 연구 결과를 토대로 공군 이러닝체계 구축에 필요한 요소를 크게 콘텐츠, 교관, 교육생, 서비스 등 4가지로 구분하고, 이에 대한 구체적인 개선 방안을 제안하였다.

• 한국생산제조학회지
• /
• 제21권4호
• /
• pp.639-643
• /
• 2012

The hip protector has been developed using the air-bag which has the capability of attenuating an impact. The impact force using the PVC air-bag was decreased by values of 27.5% on average, compared to the impact force without the air-bag. In the experiment, the standard deviation of the impact force attenuation rate was 0.78%. It means that the dimensions of the air-bag have no significant effects to reduce the impact. We believe that it is possible to design light and cheap hip protectors with air-bag to prevent the femur fracture.

• 한국진공학회:학술대회논문집
• /
• 한국진공학회 2008년도 제34회 동계학술대회 초록집
• /
• pp.76-76
• /
• 2008

• 한국항공운항학회지
• /
• 제27권1호
• /
• pp.1-9
• /
• 2019

The purpose of this study was to investigate the relationship among Calling, Role conflict, and Turnover intention of Republic of Korea Air force pilot. Specifically, we examined the mediating effect of Role conflict on the relationship between Calling and Turnover intention. Survey data from 211 Pilots in R.O.K. Air force bases were analyzed with Structural equation model, using AMOS 21.0. Results are as follows. First, Calling had negative relationships with Role conflict and Turnover intention. Second, Role conflict had a positive relationship with Turnover intention. Third, Role conflict partially mediated on the relationship between Calling and Turnover intention. These findings suggest that Calling may play a critical role in Turnover intention and Role conflict of R.O.K. Air force pilot. Finally, we discussed the implications of these results, limitations, and research suggestions for the future research.

• 한국항공운항학회지
• /
• 제31권1호
• /
• pp.1-10
• /
• 2023

This study investigated the accident cases of the U.S. Air Force and the R.O.K. Army. It analyzed the accident factors of the unmanned aircraft system using case analysis on unmanned aircraft system operators of the R.O.K. Air Force. Following the analysis this paper suggested safety operation plans for the R.O.K. Air Force. The risk factors of unmanned aircraft system were summarized by collecting and analyzing accident cases of unmanned aircraft system by the U.S. Air Force, collecting and analyzing accident risk factors of RQ-4 operators of the R.O.K. Air Force. Through the analyzed risk factors, a safety operation plan for the semi-automatic unmanned aircraft system and the fully automatic unmanned aircraft system was presented.

• 한국정보처리학회:학술대회논문집
• /
• 한국정보처리학회 2023년도 추계학술발표대회
• /
• pp.1051-1052
• /
• 2023

조류충돌(Bird Strike)은 경제적 손실, 인명적 피해를 야기하여 공군의 항공작전을 제한하는 위협요소이다. 현 공군에서는 조수퇴치조(Bird Alert Team)의 경보 발령에 의존하거나 조류의 행동을 연구하는 등 인적 역량에 의존하는 시스템을 채택하고 있다. 본 연구는 CNN을 이용하여 활주로의 유해조류를 인식 및 분류하는 자동화 시스템에 대한 제안이다. 웹캠을 활용한 실시간 유해조류를 인식하는 연구를 통해 향후 운항관제대와의 연계, 지향성 조류퇴치 장비와의 연동 방안을 제시하여 공군의 조수퇴치조(Bird Alert Team)에 대한 자동화를 실현하고 공군에서 추진중인 스마트 비행단에 이바지하고자 한다.